velvet bean

Benefits of Dopa or Velvet Bean (Mucuna Pruriens) Scrutinized

[toc]Thanks to their caffeine content, we all know coffee beans are an excellent nootropic.

Technically though, they’re not really beans.

This plant is a real bean.

It doesn’t have caffeine like coffee, but it does contain other powerful neurostimulants.

What is dopa bean used for?

Because of the fuzzy hairs which cover the young pods, it’s also known as velvet bean. In India, it’s used in traditional Ayurvedic medicine for the treatment of Parkinson’s disease. It also grows in central Africa, where it’s primarily used topically for treating venomous snake bites.

In Western culture, dopa bean supplements are used for depression, weight loss, sleep/insomnia, anxiety, opiate withdrawal, ADHD, premature ejaculation, hair and beard growth, bodybuilding, and boosting testosterone. Some of these purported health benefits have little to no scientific research. The use which has been studied most in a clinical setting is Parkinson’s.

Chemical composition and active constituents

The dopa or velvet bean nutrition facts consist of 50-60% carbs, 20-29% protein, 8-10% fiber, 6-7% fat, and 3% ash (minerals). Generally, Mucuna pruriens uses are not food, but rather the principle bioactive chemical constituent L-DOPA. It’s a neurotransmitter precursor. L-DOPA can be up to 7% of the bean powder. Some velvet bean extracts are higher.

Solaray Dopa Bean supplement

Enteric coated Solaray dopa bean is 15% L-DOPA. It’s available on Amazon.

In addition to L-DOPA, other bioactive chemical constituents found in the bean include alkaloids, saponins, and sterols, many of which are unique to the Mucuna pruriens plant. While not unique, the most noteworthy are serotonin and its precursor, 5-HTP, as well as the related bufotenin compound.

There are tetrahydroisoquinoline alkaloids, which have structures that may interact with the brain’s opioid receptors. However Mucuna pruriens is not addictive, or at least there’s no evidence of such.

Contrary to what some sources cite, there is not nicotine in Mucuna pruriens. It does contain the similar sounding nicotinamide adenine dinucleotide (NADH). That has been studied or used in connection with depression, Parkinson’s, Alzheimer’s, and chronic fatigue syndrome.

unprocessed raw dopa bean

The vitamins in velvet bean include nicotinic acid (vitamin B3) and ascorbic acid (vitamin C). The latter is relatively high, measuring up to 4.8% of the dry beans. Minerals include magnesium, iron, selenium, and iron.

As with other legumes, there are some digestive anti-nutrients in dopa bean. Glycoprotein inhibitors can inhibit the digestion of proteins. Heat deactivates them. The amount in supplement dosages is so small, it shouldn’t cause digestive side effects.

Mucunain, which is found in the hairs that cover the seed pods, causes severe skin itching and irritation. Unless contaminated, the actual beans should not contain mucunain. (1) (2) (3) (4) (5) (6) (7)

What is L-DOPA and how does it work?

In humans and many animals, L-DOPA or levodopa is an amino acid which serves as a precursor to producing the neurotransmitters dopamine, epinephrine (adrenaline), and norepinephrine (noradrenaline). The shape and structure of L-DOPA is very similar to dopamine. However the latter can’t pass the blood-brain barrier on its own, while L-DOPA can. That means it may work to boost dopamine production in the brain, which can’t be accomplished with plain dopamine.

Dopamine acts as a messenger between brain cells. It plays an important role in how our brain signals physical movement, which explains why L-DOPA might help tremors, stiffness, and loss of balance with Parkinson’s disease.

In addition to body movement, our brain releases dopamine during pleasurable activities such as eating, art, music, crafts/hobbies, socializing, and sex. This may explain the DOPA mucuna depression benefits, since the beans’ L-DOPA can serve as a precursor for the brain to make more dopamine. (8)

Mucuna pruriens benefits

The intended use of dopa bean is as a dietary supplement only. There are not sufficient studies to prove any medical benefit and therefore, it is not intended to diagnose, treat, cure, or prevent any disease. What follows are the preliminary findings on each potential benefit.

1. May improve symptoms of Parkinson’s disease

There have been a total of three peer-reviewed human clinical trials involving velvet bean extract for Parkinson’s. Results were published in 1995, 2004, and 2017. The latter two were double-blinded, while the earliest was open-label, meaning that the participants knew what they were getting.

All three trials concluded that treatment with Mucuna seed powder (i.e. dopa bean) offered improvements similar to that of levodopa medication, with possible advantages over the prescription when it came to side effects:

“…this natural source of L-dopa might possess advantages over conventional L-dopa preparations in the long term management of PD [Parkinson’s disease].”

A quote from the 2004 trial. (9)

“Adverse effects were mild and were mainly gastrointestinal in nature. No adverse effects were seen in clinical laboratory reports.”

That’s from the first trial. (10)

The latest trial from 2017 was published in Neurology. That’s the most widely read and peer-reviewed neurology journal in the world.

In the trial, a total of 18 patients with advanced Parkinson’s were randomized to receive pharmaceutical preparations (levodopa and benserazide), a dosage of Mucuna pruriens powder made from roasted beans, or a placebo.

A single treatment dose was given and their motor responses were monitored for 3 hours after.

treatment with Mucuna pruriens vs levodopa for Parkinon's side effects

The conclusion stated:

“Single-dose Mucuna pruriens [MP] intake met all noninferiority efficacy and safety outcome measures in comparison to dispersible levodopa/benserazide. Clinical effects of high-dose MP were similar to levodopa alone at the same dose, with a more favorable tolerability profile.”

Something important to emphasize is that the researchers weren’t necessarily suggesting that dopa bean is better for Parkinson’s over the standard prescription medicines.

Rather, they suggest it might be useful “as alternative source of levodopa” for people who cannot afford or have access to standardized prescription versions of it. This is why the trial took place in Bolivia, as that’s an example of a place where a low percentage of the population has access to such drugs. (11)

2. Boosting male sex hormones and sperm count

Nearly a decade ago, King George’s Medical University of India conducted two clinical trials evaluating Mucuna pruriens for male infertility.

The first, in 2008, involved 60 fertile men and 60 with infertility. A year later, the second trial did the same but with 75 men in each group.

The first study reported:

“Oligozoospermic patients [men with low sperm counts] recovered sperm concentration significantly, but sperm motility was not restored to normal levels in asthenozoospermic men [those with reduced sperm motility].”

The 2009 study had this to say after the infertile men took a dopa bean supplement for 3 months:

“Treatment with M. pruriens significantly improved testosterone, luteinizing hormone, dopamine, adrenaline, and noradrenaline levels in infertile men and reduced levels of follicle-stimulating hormone and prolactin. Sperm count and motility were significantly recovered in infertile men after treatment.”

In short, male sex hormones like testosterone, FSH, and prolactin were increased with M. pruriens, as was sperm count and motility.

What’s interesting is that prior to the start, these men measured as having low levels of dopamine, noradrenaline, and adrenaline – all of which L-DOPA is a precursor for. (12) (13)

3. Lifting mood and depression

Reviews of Mucuna pruriens for depression are prevalent online, with some even claiming it “cured my depression.” While there is theoretical science to suggest this benefit may be real, there are no human studies which have put this herbal remedy to the test.

In 2014, a pharmacy school in India did conduct an animal study. Using mice, they measured mood using:

  • Forced Swimming Test (FST)
  • Tail Suspension Test (TST)
  • Chronic Unpredictable Mild Stress (CUMS)

These tests are widely used by scientists worldwide for measuring depression in mice and rats.

dopa bean for depression

After 7 days of taking dopa bean, there was “significant antidepressant activity” according to the Forced Swimming Test and Tail Suspension Test.

“Furthermore, the results observed with MPE [Mucuna pruriens extract] treatment were largely comparable to imipramine, which suggests that MPE may produce a selective antidepressant effect.”

Based on observations of the dopamine receptors, they believe it helps depression via that mechanism. (14)

3. Darker hair and beard growth

Mucuna pruriens powder and capsules are sometimes sold and hyped for helping male facial hair growth. The theory is that it acts as a testosterone booster for beard growth.

The problem is that genetics is what largely drives whether a man can grow a thick beard, or a few scraggly hairs.

It’s not driven by how much testosterone you have, but rather how receptive your cells are to it; the thicker a beard, the more sensitive the cells are to testosterone. (15)

Even if it does boost testosterone levels, there’s not clinical validation of dopa mucuna for beard growth working. Likewise for Beardilizer and Vitabeard supplements.

One of the more unusual side effects of Mucuna pruriens may be less white and grey hair – in both men and women. If it appears in a consistent manner, this “side effect” would actually be benefit according to many.

Since its earliest use to treat Parkinson’s disease, levodopa medication has been associated with hair and beard darkening. Since Mucuna pruriens extract is a natural source of L-DOPA, it’s not surprising that some supplement users have reported the same. (16)

grey hair before and after photos with mucuna pruriens powder

This photo comes from a case study a 62 year old Parkinson’s patient who had less grey hair and restored pigmentation in some areas, after supplementing with Mucuna pruriens. The doctor who authored it reports:

“DOPA/dopamine are intermediate metabolites in the production of melanin, therefore, this association is not surprising.”

The reason this complication is far less common with prescription levodopa is because now, most of them include decarboxylase inhibitors, which would block that. (17)

5. Libido, ED, and premature ejaculation

Along with ashwagandha and tribulus, DOPA macuna has been used for the treatment of sexual dysfunction in Ayurvedic medicine. Mainly as an aphrodisiac and libido booster, which includes helping men with erectile dysfunction. Some supplements users claim it helps premature ejaculation. Uses for women are less common.

When it comes to velvet bean uses for sexual benefits, almost no formal research exists.

In 2009, an Indian university did publish a study with rats and reported:

“The extract administered PO [taken by mouth] significantly increased the mounting frequency, intromission frequency and ejaculation latency, and decreased the mounting latency, intromission latency, post-ejaculatory interval and inter-intromission interval. The potency test significantly increased erections, quick flips, long flips and total reflex. Therefore, the results indicated that the ethanolic extracts of Mucuna pruriens Linn. seed produced a significant and sustained increase in the sexual activity of normal male rats at a particular dose (200mg/kg).”

In shot, it made them horny. (18)

A 2016 study out of a Turkish university tested it on rats, along with the other two common Ayurvedic herbs for sex; ashwagandha and tribulus. They pitted their performance against sildenafil (Viagra). The reported:

“…results demonstrate for the first time that Mucuna, Tribulus and Ashwagandha supplementation improves sexual function in male rats via activating Nrf2/ HO-1 pathway while inhibiting the NF-κB levels.”

In plain English, the herb appears to benefit pathways related to sexual function. (19)

6. Natural remedy for better sleep

Dopa bean for sleep is one of the more common uses for the supplement. There is no clinical research on this, neither in humans or animals. In theory it may help you sleep better, since it contains 5-HTP, which is the precursor to serotonin and melatonin.

7. Bodybuilding

While there is no formal research measuring muscle growth and recovery with a Mucuna pruriens supplement, they are popular among bodybuilders. Unlike the many snake oil supplements for sale today, this one might really help; it has been proven to increase testosterone levels in human clinical trials.

The catch is that those men had fertility issues. It’s unknown whether normal, healthy men would also experience a boost in testosterone. If they did, it may indeed help support muscle growth, particularly in men who are middle-aged and older.

8. Weight loss

Unlike green tea which revs up metabolism and baobab fruit which suppresses appetite, Mucuna pruriens extract is purported to work for weight loss in a different way; through boosting mood, which motivates more physical activity (e.g. working out).

As with bodybuilding, this benefit does seem theoretically possible, though it has yet to be studied. If the bean powder or extract is supporting dopamine levels and making one feel less depressed, it’s plausible that it could help one lose weight.

Mucuna pruriens side effects

Because there are only several human clinical trials to date, possible adverse reactions from using Mucuna pruriens are not well understood. Relative to placebo, no significant side effects have been observed in the trials, with the exception of vomiting.

That was seen with one patient and it was believed to be related to the digestability of the beans, rather than their chemical constituents. The dosage in the trial was large; 15-30g of powder. (20)

Since Mucuna pruriens naturally contains L-DOPA, drug interactions with antidepressants and Parkinson’s disease treatments would be expected.

Case studies documenting a Mucuna pruriens allergy have not been published, though reactions remain possible. Even without an allergy to dopa bean, one would be expected to experience hives and skin irritation if their supplement was contaminated with the “hairs” that cover the young seed pods. That fuzzy fur contains mucunain, which most humans react to.

Safety of using dopa bean during pregnancy or while breastfeeding is unknown. It has not been tested in pregnant humans or animals.

You should consult your doctor before using this supplement.

How and when to take

mucuna pruriens dosage recommendations

The typical velvet bean extract supplement contains 500-1,000 mg of powder per dose. Usually the powder is inside gelatin or vegan capsules, with 2 capsules equaling 1 daily dose/serving. Some manufacturers recommend splitting the dose, with the best time to take it being in the morning and again in the afternoon. It can be taken with or without food.

Supplement reviews & where to buy

It’s not the type of supplement you’re going to find for sale at Walmart or Walgreen’s. Mucuna pruriens at Vitamin Shoppe, GNC, Holland and Barrett (United Kingdom) and similar stores will be your best bet. Because it’s more of an Indian Ayurvedic herb, it’s not something commonly sold in westernized cultures.

On Amazon, the following are all good brands that we trust:

Himalaya Organic

What’s nice about this supplement is that it contains 350 mg of velvet bean stem powder and 250 mg of the bean extract, which has 6% L-DOPA. Using both parts provides a more diverse profile of the plant’s constituents. You can buy a bottle of 60 caplets.

NOW Foods

This is a stronger supplement based on L-DOPA; a minimum 15% concentration is listed on the label. Each serving of 2 veggie capsules (vegan, non-gelatin) contain 800 mg of the velvet bean exract. You can buy a 90 capsule bottle which equates to 45 servings.

Bulk Mucuna pruriens extract powder

While they don’t report the concentration of L-DOPA it contains, the brand BulkSupplements sells 100% pure velvet bean powder in a 100g bag.


These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Main photo by Ananya Mondal via Wikipedia [CC by 3.0]