Best 9 Nootropics (Smart Drugs) To Unlock Your Full Potential

Nootropics; sometimes referred to as smart drugs – are compounds that enhance brain function. They’re becoming a common way to give an extra boost to your mind. According to one Telegraph survey, up to 25 percent of students at leading UK universities have taken the prescription smart drug modafinil [1], and California tech start-up workers are trying everything from Adderall to LSD to drive their brains to a higher gear[2].

I have been actively benefiting from nootropics since 1997 when I was struggling with cognitive performance and ordered nearly $1000 worth of smart drugs from Europe (the only place where you could get them at that time). I remember opening the unmarked brown package and wondering if the pharmaceuticals and natural substances would really make my brain better.

They did, and I’ve been a big fan of some cognitive enhancers ever since.

But I’m suspicious of the others. The trouble with using a general term like “nootropics” is that you lump all kinds of substances together. Technically, you could argue that both caffeine and cocaine are nootropics, but they’re hardly the same. With so many ways to enhance your brain function, many of which have significant risks, it is most important to look at nootropics on a case-by-case basis. Here’s a list of 9 nootropics, along with my thoughts on each of them.

Modafinil (Provigil), Armodafinil (Nuvigil), Adrafinil

Focus, motivation, clarity, and memory.

I started taking modafinil while I was receiving my MBA at Wharton. At the same time, I was also working at a start-up that was later sold for $600 million in cash, so you can imagine how busy I was. I was looking for a way to keep my brain running.

When I started taking modafinil for the first time, I felt more like myself than I had in years. I took it at different doses every day for 8 years (with a doctor’s prescription). It gave me energy, and it changed my life. I wouldn’t be a biohacker without modafinil today.

When I was working on the Bulletproof Diet book, I wanted to check that the results I was getting from Bulletproof Coffee didn’t come from modafinil, so I quit using it and tested my cognitive performance when I was out of it. What I noticed was that my emotional performance on Bulletproof Coffee and Bulletproof Diet was almost the same as my performance on modafinil. I’m still traveling with modafinil, and I’m going to take it occasionally, but I rarely feel the need while living a Bulletproof lifestyle.

There is a slight risk (about 5 in a million people) of having a life-threatening immune response to modafinil. It’s the same reaction that occurs with ibuprofen and other NSAIDs (non-steroidal anti-inflammatory drugs), so if you know that you don’t respond well to NSAIDs, talk to your doctor before taking modafinil.

One reason I like modafinil is that it stimulates the release of dopamine, but it binds to your dopamine receptors differently than addictive substances like cocaine and amphetamines do, which may be part of the reason that modafinil provides many of the advantages of other stimulants but does not trigger addiction or withdrawal symptoms. [3][4] It does increase concentration, problem-solving, and alertness, but it is not in the same class of drugs as Adderall, and it is not a traditional stimulant. Modafinil is patent-free, so you can get it generically, or order it from India. It’s a prescription drug, so you need to talk to a doctor about it.

You can also seek armodafinil, a more refined form of modafinil, with only biologically similar molecules in it. It has almost the same and sometimes stronger effects. Without insurance, it’s very expensive.

If you don’t want to get a prescription, there’s adrafinil, which has similarities, but I wouldn’t recommend taking it regularly, because it’s a lot of stress on your liver.

Normally prescribed modafinil dose: 50-200 mg, taken in the morning (unless you want to be awake all night) Normally prescribed armodafinil dose: 100-200 mg, taken in the morning Adrafinil dose: 300 mg, taken in the morning.


Focus, mood, motivation

Nicotine is a smart drug: picture of sunrise tobacco plants Nicotine can be a potent nootropic if you take it carefully and sp. Here is a complete guide to the use of nicotine as a nootropic, complete with pros and cons, risks, dose recommendations, and advice on what kind of nicotine to use.

I don’t recommend smoking cigarettes or using tobacco to get nicotine. I’m thinking about very small doses that are much smaller than you would get from smoking. Nicotine has a direct effect on your mitochondrial energy, and just about anything that increases mitochondrial function will make your brain work better.

Amphetamine (Adderall)

Focus… but with high risk and several drawbacks

Big Pharma has been recommending amphetamine (Adderall) for ADHD sufferers for years to come. It’s also popular at college campuses around the time of the exam. Too bad, because there are a lot of better choices.

Amphetamine is at considerable risk. In healthy adults, it improves attention, focus, motivation to work, and short-term memory, all by increasing the release of dopamine and norepinephrine in your prefrontal cortex. [5][6] Amphetamine also reduces fatigue, but it makes you jittery and can increase anxiety.

What concerns me about amphetamine is its addictive potential and the fact that it can cause stress and anxiety. Research says that it is only slightly likely to cause addiction in people with ADHD [7], but we don’t know much about its addictive potential in healthy adults. We all know about the addictive potential of methamphetamine, and amphetamine is closely related enough to make me nervous about so many people giving it to their children. Amphetamines induce withdrawal symptoms, so there is a risk for addiction.

If you want to have a stimulant, drink some coffee.

Forskolin & artichoke extract

Memory, focus, learning

Because smart drugs like modafinil, nicotine, and Adderall come with drawbacks, I have developed my own line of nootropics, including Forbose and SmartMode, which is safe, widely available, and does not require a prescription.

Forskolin, found in Forbose, has been part of Indian Ayurvedic medicine for thousands of years. In addition to being fun to say, forskolin increases cyclic adenosine monophosphate (cAMP), a molecule essential for learning and memory formation. [8] I have been using forskolin for more than a decade.

Forskolin is particularly effective if you combine it with an artichoke extract. Artichoke extract inhibits PDE4, an enzyme that breaks down the cAMP. PDE4 inhibitors make cAMP more available, and when you add cAMP-enhancing effects to your artichoke extract, you get a significant boost to learning, memory, and motivation.

Or you get a headache and an energy crash when you “come down.” That might be because cAMP upping uses more dopamine than your brain would normally do. It affects different people in a different way. All you know is if you try it.

As part of our Bulletproof Brain Mix, Smart Mode includes artichoke extract and other cognitive-enhancing ingredients. Taking Forbose to get your dose of forskolin. Forbose is a special product that helps the body create more energy to power through vigorous physical and mental exercise.


A calm alertness, reaction time, mental endurance

L-theanine is a major component of black and green tea. Theanine, on its own, promotes relaxation,[9] alertness and excitement. [10]

Theanine also works with caffeine synergistically. Together, they increase response time, memory, and mental endurance. [11]

You can get your theanine from a capsule-like Zen Mode, or you can have a cup of green tea or two. If you decide to make green tea, look for tea that’s grown in the shade, because shade-grown green tea tends to have much higher levels of theanine.

A dose of L-theanine: 200 mg. Take 3 Zen Mode soft gels with your morning coffee or take it at night like me.

Bacopa Monnieri

Attention, mood, stress, memory

This is a small water plant native to India. Bacopa is an adaptive agent–it helps your body to adapt to stress. It also improves memory in healthy adults[12] and enhances attention and mood in people over 65 years of age. 13] Scientists still don’t fully understand how Bacopa works, but they do know it takes time to work; study participants didn’t feel its memory-enhancing effects until they had been supplementing it every day for 4 weeks, so if you try Bacopa, stick with it for a month before you give it up.

Bacopa suppresses sperm production in male mice, so if you’re trying to conceive, you might want to skip it. 14] However, it did not affect the testosterone or sex drive of the mice.

Many nootropic companies include Bacopa in their stacks, but they often do not use enough to give you real benefits. You want at least 750 mg a day. Take Bacopa with a fat source to increase absorption.

Bacopa monnieri dose: at least 750 mg daily, taken with a fat source

CoEnzyme Q10

Energy, clarity

Unfair Advantage supports your mitochondria, the power plants of your cells, with two different ingredients: CoQ10 enhances cellular energy production in your mitochondria, giving you both a mental and physical boost. 15] (The dose of CoQ10 is low, but it is in a colloidal form that enhances the delivery of PQQ) ActivePQQTM is a novel form of PQQ that is not inactivated by stomach acid. PQQ promotes the growth of new mitochondria and also helps your body clear up and replace old mitochondria. 16] You have the highest density of mitochondria in your brain’s prefrontal cortex, which helps explain why I first feel the Unfair Advantage in my head. You have the second-highest density in your heart, which is likely why I feel it next in the center of my chest. Mitochondrial energizers may have profound nootropic effects! At higher doses, mitochondrial energizers also make excellent pre-workout supplements.

Unfair Advantage Dose: 1-4 ampules, taken at any time


energy, stress

KetoPrime is another powerful nootropic. It contains oxaloacetate, a compound that can protect your brain from environmental toxins.

Common environmental toxins–pesticides, for instance–cause your brain to release glutamate (a neurotransmitter). Your brain needs glutamate to function, but when you make too much of it, it becomes toxic and begins to kill neurons.

Oxaloacetate protects rodents from brain damage caused by glutamate.[17] Of course, more research is needed to determine whether or not oxaloacetate has the same effect on humans.

KetoPrime is a great way to give a little extra boost to your brain. In animal studies, the Krebs Cycle is also modified, shifting the ratio of NADH to NAD+, making mitochondrial energy production more efficient.

KetoPrime Dose: 1 lozenge, taken in the morning


Memory and Focus

NeuroMaster is a supplement that I helped to formulate when I learned about the power of coffee fruit extract. This significantly increases the level of the brain-derived neurotrophic factor (BDNF)–even more than exercise. BDNF is a key neuroprotein that helps increase neuroplasticity and create new neurons, resulting in better memory and focus.

This is important for the short term and is essential for the long term because you naturally lose BDNF as you age. Lower BDNF levels are associated with age-related hippocampal shrinkage and memory decline.[18] In several studies, 100 mg of coffee fruit extract (red fruit surrounding coffee beans) increased BDNF by approximately 140 percent.[19][21] The boost lasted a few hours.

Dose NeuroMaster: 1 cap, taken in the morning with or without food. You should know about nootropics. When you start taking nootropics for the first time, sometimes you feel like nothing is going on. That’s exactly what I’ve experienced. Then, a week later, I stopped taking them and immediately noticed their absence. This is because when your brain works better, it feels so natural that it’s hard to see unless you have a high degree of self-awareness.

On the other hand, sometimes, you feel a significant cognitive boost as soon as you take a pill. It could be a good thing or a bad thing. For example, I find that modafinil makes you more of what you already are. That means, if you’re already kind of a dick and you’re taking modafinil, you might act like a big dick and regret it. It definitely happened to me! I like to think that I’ve done enough to hack my brain to get through that programming… and that when I use nootropics, they help me help people.

You can also get deeply depressed. One of the nootropics I haven’t written about here, Lucidril, has excellent anti-aging and cognitive benefits for some. Still, others get deeply sad after taking it. After three days on Lucidril, I felt hopeless about my life. Luckily, I did my research, and I stopped taking it right away.

There is an inherent risk of experimenting with pharmaceuticals or illegal drugs such as LSD. The risk is higher than that of most natural substances. You may have a psychotic experience if you take too much LSD; you are more likely to have a severe headache if you take too much of a choline-stimulating herbal substance.

It’s also worth checking the purity of your nootropics. I’ve seen some companies promoting pre-made nootropic stacks that contain ingredients such as blue agave (fructose!), food coloring–even metal pieces. Read the labels!

I have high hopes that the medicine will wake up to the fantastic benefits of nootropics and begin to be incorporated into society. Not only do many of them increase your quality of life, but they also make your brain more resilient to the environment around you. We could all use a little more of that.

Before you try nootropics, I suggest you start with the basics: get rid of things in your diet and life that first reduces cognitive performance. That’s the easiest. Then add energizers such as Brain Octane and clean up your diet. Then go to herbals and natural nootropics. Use drugs selectively only after you’ve figured out your basics.

The truth is, almost 20 years ago, when my brain failed, and I was fat and tired, I didn’t know how to follow this advice. I bought $1000 worth of smart drugs from Europe, took them all out of desperation at once, and had enough cognitive function to save my career and solve my metabolic problems.

You don’t need to do that with the information we have now. Please learn from my mistakes, please!

Medications That Changes Who We Are

“Patient Five” was in his late 50s when a trip to the doctors changed his life.

He had diabetes, and he had signed up for a study to see if taking a “statin” – a kind of cholesterol-lowering drug – might help.

So far, so normal.

But soon after he began the treatment, his wife began to notice a sinister transformation.

A previously reasonable man, he became explosively angry and – out of nowhere – developed a tendency for road rage.

During one memorable episode, he warned his family to keep away, lest he put them in hospital.

Out of fear of what might happen, Patient Five stopped driving. Even as a passenger, his outbursts often forced his wife to abandon their journeys and turn back. Afterward, she’d leave him alone to watch TV and calm down. She became increasingly fearful for her own safety.

Then one day, Patient Five had an epiphany. “He was like, ‘Wow, it really seems that these problems started when I enrolled in this study,'” says Beatrice Golomb, who leads a research group at the University of California, San Diego.

Alarmed, the couple turned to the study’s organizers. “They were very hostile. They said that the two couldn’t possibly be related, that he needed to keep taking the medication, and that he should stay in the study,” says Golomb.

Ironically, by this point, the patient was so cantankerous that he flatly ignored the doctors’ advice. “He swore roundly, stormed out of the office, and stopped taking the drug immediately,” she says. Two weeks later, he had his personality back.

Others have not been so lucky. Over the years, Golomb has collected reports from patients across the United States – tales of broken marriages, destroyed careers, and a surprising number of men who have come unnervingly close to murdering their wives.

In almost every case, the symptoms began when they started taking statins, then promptly returned to normal when they stopped; one man repeated this cycle five times before he realized what was going on.

Antidepressants may not just lighten moods, they may also reduce expressions of neuroticism, research suggests.

According to Golomb, this is typical – in her experience, most patients struggle to recognize their own behavioral changes, let alone connect them to their medication. In some instances, the realization comes too late: the researcher was contacted by the families of a number of people, including an internationally renowned scientist and a former editor of a legal publication, who took their own lives.

We’re all familiar with the mind-bending properties of psychedelic drugs – but it turns out ordinary medications can be just as potent. From paracetamol (known as acetaminophen in the US) to antihistamines, statins, asthma medications, and antidepressants, there’s emerging evidence that they can make us impulsive, angry, or restless, diminish our empathy for strangers, and even manipulate fundamental aspects of our personalities, such as how neurotic we are.

In most people, these changes are extremely subtle. But in some, they can also be dramatic.

The list of potential culprits includes some of the most widely consumed drugs on the planet

Back in 2011, a French father-of-two sued the pharmaceutical company GlaxoSmithKline, claiming that the drug he was taking for Parkinson’s disease had turned him into a gambler and gay sex addict, and was responsible for risky behaviors that had led to him being raped.

Then in 2015, a man who targeted young girls on the internet used the argument that the anti-obesity drug Duromine made him do it – he said that it reduced his ability to control his impulses. Every now and again, murderers try to blame sedatives or antidepressants for their offenses.

If these claims are true, the implications are profound. The list of potential culprits includes some of the most widely consumed drugs on the planet, meaning that even if the effects are small at an individual level, they could be shaping the personalities of millions of people. 

Research into these effects couldn’t come at a better time. The world is in the midst of a crisis of over-medication, with the US alone buying up 49,000 tonnes of paracetamol every year – equivalent to about 298 paracetamol tablets per person – and the average American consuming $1,200 worth of prescription medications over the same period. And as the global population ages, our drug-lust is set to spiral even further out of control; in the UK, one in 10 people over the age of 65 already takes eight medications every week.

In the US, more than 49,000 tons of paracetamol is consumed every year – the equivalent of 298 pills per person.

How are all these medications affecting our brains? And should there be warnings on packets?

Golomb first suspected a connection between statins and personality changes nearly two decades ago, after a series of mysterious discoveries, such as that people with lower cholesterol levels are more likely to die violent deaths. Then one day, she was chatting to a cholesterol expert about the potential link in the hallway at her work when he brushed it off as obvious nonsense. “And I said ‘how do we know that?’,” she says.

Filled with fresh determination, Golomb scoured the scientific and medical literature for clues. “There was shockingly more evidence than I had imagined,” she says. For one thing, she uncovered findings that if you put primates on a low-cholesterol diet, they become more aggressive.

Golomb remains convinced that lower cholesterol can cause behavioral changes in both men and women

There was even a potential mechanism: lowering the animals’ cholesterol seemed to affect their levels of serotonin, an important brain chemical thought to be involved in regulating mood and social behavior in animals. Even fruit flies start fighting if you mess up their serotonin levels, but it also has some unpleasant effects in people – studies have linked it to violence, impulsivity, suicide, and murder.

If statins were affecting people’s brains, this was likely to be a direct consequence of their ability to lower cholesterol. 

Since then, more direct evidence has emerged. Several studies have supported a potential link between irritability and statins, including a randomized controlled trial – the gold-standard of scientific research – that Golomb led, involving more than 1,000 people. It found that the drug increased aggression in post-menopausal women, though, oddly, not in men.

In 2018, a study uncovered the same effect in fish. Giving statins to Nile tilapia made them more confrontational and – crucially – altered the levels of serotonin in their brains. This suggests that the mechanism that links cholesterol and violence may have been around for millions of years.

Golomb remains convinced that lower cholesterol and, by extension, statins can cause behavioral changes in both men and women, though the strength of the effect varies drastically from person to person. “There are lines of evidence converging,” she says, citing a study she conducted in Sweden, which involved comparing a database of the cholesterol levels of 250,000 people with local criminal records. “Even adjusting for confounding factors, it was still the case that people with lower cholesterol at baseline were significantly more likely to be arrested for violent crimes.”.

Fruit flies become more aggressive when their serotonin levels become mixed up; research has shown.

But Golomb’s most unsettling discovery isn’t so much the impact that ordinary drugs can have on who we are – it’s the lack of interest in uncovering it. “There’s much more of an emphasis on things that doctors can easily measure,” she says, explaining that, for a long time, research into the side-effects of statins was all focused on the muscles and liver, because any problems in these organs can be detected using standard blood tests.

This is something that Dominik Mischkowski, a pain researcher from Ohio University, has also noticed. “There is a remarkable gap in the research actually when it comes to the effects of medication on personality and behavior,” he says. “We know a lot about the physiological effects of these drugs – whether they have physical side effects or not, you know. But we don’t understand how they influence human behavior.”

Mischkowski’s own research has uncovered a sinister side-effect of paracetamol. For a long time, scientists have known that the drug blunts physical pain by reducing activity in certain brain areas, such as the insular cortex, which plays an important role in our emotions. These areas are involved in our experience of social pain, too – and intriguingly, paracetamol can make us feel better after a rejection.

Mischkowski wondered whether painkillers might be making it harder to experience empathy

And recent research has revealed that this patch of cerebral real-estate is more crowded than anyone previously thought because it turns out the brain’s pain centers also share their home with empathy.

For example, fMRI (functional magnetic resonance imaging) scans have shown that the same areas of our brain become active when we’re experiencing “positive empathy” –pleasure on other people’s behalf – as when we’re experiencing pain.

Given these facts, Mischkowski wondered whether painkillers might be making it harder to experience empathy. Earlier this year, together with colleagues from Ohio University and the Ohio State University, he recruited some students and spilled them into two groups. One received a standard 1,000mg dose of paracetamol, while the other was given a placebo. Then he asked them to read scenarios about uplifting experiences that had happened to other people, such as the good fortune of “Alex,” who finally plucked up the courage to ask a girl on a date (she said yes).

L-dopa is the most successful treatment for Parkinson’s, but it can have side effects, making people act more impulsively. 

The results revealed that paracetamol significantly reduces our ability to feel positive empathy – a result with implications for how the drug is shaping the social relationships of millions of people every day. Though the experiment didn’t look at negative empathy – where we experience and relate to other people’s pain – Mischkowski suspects that this would also be more difficult to summon after taking the drug.

“I’m not entirely junior anymore as a researcher, and to be honest, this line of research is really the most worrisome that I’ve ever conducted,” he says. “Especially because I’m well aware of the numbers [of people] involved. When you give somebody a drug, you don’t just give it to a person – you give it to a social system. And we really don’t understand the effects of these medications in the broader context.”

Empathy doesn’t just determine if you’re a “nice” person, or if you cry while you’re watching sad movies. The emotion comes with many practical benefits, including more stable romantic relationships, better-adjusted children, and more successful careers – some scientists have even suggested that it’s responsible for the triumph of our species. In fact, a quick glance at its many benefits reveals that casually lowering a person’s ability to empathize is no trivial matter. 

Scientists have known for a while that the medications used to treat asthma are sometimes associated with behavioral changes, such as an increase in hyperactivity

Technically, paracetamol isn’t changing our personalities because the effects only last a few hours, and few of us take it continuously. But Mischkowski stresses that we do need to be informed about the ways it affects us so that we can use our common sense. “Just like we should be aware that you shouldn’t get in front of the wheel if you’re under the influence of alcohol, you don’t want to take paracetamol and then put yourself into a situation that requires you to be emotionally responsive – like having a serious conversation with a partner or co-worker.”

One reason medications can have such psychological clout is that the body isn’t just a bag of separate organs, awash with chemicals with well-defined roles – instead, it’s a network, in which many different processes are linked.

For example, scientists have known for a while that the medications used to treat asthma are sometimes associated with behavioral changes, such as an increase in hyperactivity and the development of ADHD symptoms. Then, more recently, the research uncovered a mysterious connection between the two disorders themselves; having one increases the risk of having the other by 45-53%. No one knows why, but one idea is that asthma medications bring on ADHD symptoms by altering levels of serotonin or inflammatory chemicals, which are thought to be involved in the development of both conditions.

There have been many reports of severe psychological change from the use of statins.

Sometimes these links are more obvious. Back in 2009, a team of psychologists from Northwestern University, Illinois, decided to check if antidepressants might be affecting our personalities. In particular, the team was interested in neuroticism. This “Big Five” personality trait is epitomized by anxious feelings, such as fear, jealousy, envy, and guilt.

For the study, the team recruited adults who had moderate to severe depression. They gave one-third of the study’s participants the antidepressant paroxetine (a kind of selective serotonin reuptake inhibitor (SSRI)), one third a placebo, and one third talking therapy. They then checked to see how their mood and personalities changed from the beginning to the end of a 16-week treatment.

“We found that massive changes in neuroticism were brought about by the medicine and not very much at all by the placebo [or therapy],” says Robert DeRubeis, who was involved in the study. “It was quite striking.”

The idea that antidepressants are affecting neuroticism directly is intriguing

The big surprise was that, though the antidepressants did make the participants feel less depressed, the reduction in neuroticism was much more powerful – and their influence on neuroticism was independent of their impact on depression. The patients on antidepressants also started to score more highly for extroversion.

It’s important to note that it was a relatively small study, and no one has tried to repeat the results yet, so they may not be totally reliable. But the idea that antidepressants are affecting neuroticism directly is intriguing. One idea is that the trait is linked to the level of serotonin in the brain, which is altered by the SSRIs. 

While becoming less neurotic might sound like an appealing side-effect, it’s not necessarily all good news. That’s because this aspect of our personalities is something of a double-edged sword; yes, it’s been associated with all kinds of unpleasant outcomes, such as an earlier death, but it’s also thought that anxious over-thinking might be helpful. For example, neurotic individuals tend to be more risk-averse, and in certain situations, worrying can improve a person’s performance.

Cholesterol-lowering drugs save tens of thousands of lives every year, so people should seek medical advice before stopping taking them.

“What [the American psychiatrist] Peter Kramer warned us about was that when some people are on antidepressants, what can happen is that they begin not to care about things that people care about,” says DeRubeis. If the results do hold up, should patients be warned about how their treatment might change them?

“If I were advising a friend, I would certainly want them to be on the lookout for those kinds of undesirable effects, just like they would naturally be looking out for other side-effects, like whether they’re gaining weight, and so on,” says DeRubeis.

At this point, it’s worth pointing out that no one is arguing that people should stop taking their medication. Despite their subtle effects on the brain, antidepressants have been shown to help prevent suicides, cholesterol-lowering drugs save tens of thousands of lives every year, and paracetamol is on the World Health Organisation’s list of essential drugs because of its ability to relieve pain. But it is important that people are informed about any potential psychological side-effects.

The association with impulsive behaviors makes sense because L-dopa is essentially providing the brain with a dose of extra dopamine

The matter takes on a whole new urgency when you consider that some personality changes can be dramatic. There’s solid evidence that the drug L-dopa, which is used to treat Parkinson’s disease, increases the risk of Impulse Control Disorders (ICDs) – a group of problems that make it more difficult to resist temptations and urges.

Consequently, the drug can have life-ruining consequences, as some patients suddenly start taking more risks, becoming pathological gamblers, excessive shoppers, and sex pests. In 2009, a drug with similar properties hit the headlines after a man with Parkinson’s committed a £45,000 ($60,000) ticket scam. He blamed it on his medication, claiming that it had completely changed his personality.

The association with impulsive behaviors makes sense because L-dopa is essentially providing the brain with a dose of extra dopamine – in Parkinson’s disease, the part of the brain that produces it is progressively destroyed – and the hormone is involved in providing us with feelings of pleasure and reward.

Experts agree that L-dopa is the most effective treatment for many of the symptoms of Parkinson’s disease, and it’s prescribed to thousands of people in the US every year. This is despite a long list of possible side effects that accompany the medication, which explicitly mentions the risk of unusually strong urges, such as for gambling or sex.

In fact, DeRubeis, Golomb, and Mischkowski are all of the opinion that the drugs they’re studying will continue to be used, regardless of their potential psychological side-effects. “We are human beings, you know,” says Mischkowski. “We take a lot of stuff that is not necessarily always good in every circumstance. I always use the example of alcohol, because it’s also a painkiller like paracetamol. We take it because we feel that it has a benefit for us, and it’s OK as long as you take it in the right circumstances, and you don’t consume too much.”.

But in order to minimize any undesirable effects and get the most out of the staggering quantities of medications that we all take each day, Mischkowski reiterates that we need to know more. Because at the moment, he says, how they are affecting the behavior of individuals – and even entire societies – is largely a mystery. 

By Zaria Gorvett, BBC