5-HTP Benefits

5-HTP – Benefits, Side Effects, Dosage

5-HTP (5-hydroxytryptophan) is a precursor to the happiness hormone serotonin. It increases the serotonin level in the brain. Serotonin is involved in happiness and appetite regulation. 5-HTP reduces appetite, especially for sweets and carbohydrates, resulting in weight loss in several studies.

Our  Shop offers a 5-HTP product with a very pure 5-HTP 99% extract from the Griffonia simplicifolia plant, with 125 mg 5-HTP per capsule.

5-HTP is the precursor of the happiness hormone serotonin.

5-HTP for losing weight

According to some clinical studies, 5-HTP has an appetite suppressing effect and reduces the consumption of carbohydrates after ingestion. This has resulted in weight loss in some studies, which is without a diet at 1 kg in 6 weeks and with a targeted diet in a range of 0.5 – 1kg per week. 5-HTP shows a tendency to reduce the appetite for carbohydrates and sweets. This appetite-suppressing 5-HTP effect is likely to result from the elevated serotonin level because happiness hormone is also released after eating carbohydrates. The ingestion of 5-HTP mimics that.

Unfortunately, the current number of studies and the quality of the studies are not enough to clearly recommend 5-HTP as an efficient weight-loss aid, according to the European Food Safety Authority. Please read the detailed description of the studies below.

5-HTP is often combined with L-carnitine by users.

5-HTP for depression and restlessness

5-HTP has been shown to work in depression, according to two clinical studies. However, there is currently insufficient qualitative study material to recommend it as an alternative, established therapy for depression, as more research is needed. 5-HTP has an immediate anxiolytic effect in people with panic attacks, but the research for this is also very minor.

5-HTP for better sleep

5-HTP is likely to help with sleep problems by causing an increase in the sleep hormone melatonin, but again there are no exact studies that should be done with 5-HTP alone, with no other active ingredients.

5-HTP side effects

5-HTP is a safe drug, but under no circumstances should it be used in combination with antidepressants for the risk of serotonin syndrome without medical supervision and is not a substitute for medical treatment.

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5-HTP Efficacy in Humans: The European Food Safety Authority (EFSA) has never considered that 5-HTP has a health or physiological relevance in healthy humans as sufficiently scientifically proven.


5-HTP (5-hydroxytryptophan, L-5-hydroxytryptophan) is a direct precursor to the neurotransmitter serotonin, which is responsible for happiness. The oral administration of 5-HTP is well absorbed, traversing the blood-brain barrier and reliably increasing serotonin synthesis in the central nervous system (CNS) (1). In contrast, the amino acid L-tryptophan must first be converted to 5-HTP, which is two steps away from serotonin and its conversion is more tightly regulated.

5-THP is offered as a dietary supplement and is often obtained from the plant Griffonia Simplicifolia. As a rule, a Griffonia simplicifolia extract contains 20% 5-HTP. 250 mg of the extract thus correspond to 50 mg of 5-HTP. Since the Griffonia simplicifolia extract also contains other active ingredients, the effect could be different from the chemically pure 5-HTP.

Heading 5-HTP and Weight Loss

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The happiness hormone serotonin is an important regulator of appetite and its release is reduced by dieting. This leads to cravings, which are often eradicated by sugar and carbohydrates, because these raise the serotonin again. In qualitative studies, 5-HTP already achieved a low daily dose (8 mg / kg body weight) and without a prescribed diet a weight loss of 1 kg in 6 weeks. At a higher dose and along with a diet, it resulted in a decrease of 3.3 kg within 6 weeks. In another study, diabetics decreased 2 kg within 2 weeks with a daily dose of 750 mg 5-HTP.


The happiness hormone serotonin plays one of the central roles in appetite regulation (2). In particular, it docks at the serotonin receptor 5-HT2C, triggering the release of appetite-suppressing messengers (3). People who are on a high-calorie diet have increased levels of depletion and lower blood levels of the amino acid L-tryptophan (4, 5). Tryptophan is a precursor of 5-HTP and therefore of serotonin. The decreased tryptophan concentration results in a worsened mood and increased appetite.

A craving for sugary foods during or after a diet is typical. Consumption of these foods increases serotonin release and temporarily lifts spirits, but results in guilt, frustration and rejuvenation out of frustration. This leads to a vicious circle and a yo-yo effect (6, 7).

Medications such as dexfenfluramine and sibutramine, which are mainly involved in serotonin regulation, have been used successfully to combat obesity (8, 9). However, the cardiovascular side effects of these drugs led to regulatory withdrawal from the market (10, 11).

Since 5-HTP stimulates serotonin production in the brain, it also aroused interest in the fight against obesity and appetite-suppressing support in weight loss.

As early as 1989, a double-blind, placebo-controlled study in so-called crossover design was conducted on obese women. Cross Over means in this case that for 5 weeks some women got the 5-HTP, and another did not, then they swapped. It is very useful to research the efficiency of a drug. The participants did not follow a diet and only received a dose of 8 mg / kg / day 5-HTP. A woman weighing 100 kg would therefore have taken 80 mg 5-HTP daily. The dose was divided into three takings and the pills were taken half an hour before each of the three meals.

The treated women were able to lose on average 1 kg of body weight within 5 weeks compared to those receiving the placebo. An additional prescribed diet in combination with the 5-HTP would have been able to achieve much more, according to the researchers. Also interesting is the dose used, which compared to other studies was relatively low and still achieved very good results.

In another double-blind, placebo-controlled study, the same researchers tried to find out if 5-HTP would work better with a diet. Obese women were given a 5-HTP dose of 900 mg / day for 6 weeks, and in the next 6 weeks they were prescribed a reduced-calorie diet in addition to 5-HTP. The women lost 1.7 kg in the first part of the study, in the second part of the study they lost 3.3 kg of body weight. Overall, the weight reduction averaged 5 kg within 12 weeks (12).

For diabetic patients, who often have a craving for food and carbohydrates, 5-HTP was given for two weeks. The daily dose was 750 mg, divided into three 250 mg receipts, half an hour before each meal. The participants were able to lose 2.1 kg after two weeks without an additional diet (13).

A combination of the extract of Griffonia Simplicifolia (5-HTP) and other plants [including guarana (caffeine), Alga klamath (phenylethylamine)] was administered in a spray sublingually (under the tongue). This study on healthy, obese women was double-blind, placebo-controlled and ran for two months. A light diet was prescribed to both the 5-HTP and the placebo group. Thanks to the 5-HTP, the participants were able to reduce the body mass index (BMI) by 0.8 kg / m² and significantly reduce body fat (14).

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5-HTP AS An Appetite Suspressant

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5-HTP lowered food intake in a range of 21-42% in 3 placebo-controlled, double-blind studies. Study participants ate fewer carbohydrates than usual, intake of carbohydrates and sugars decreased by 25% -50%. It is still unclear whether 5-HTP is more likely to inhibit hunger / appetite or increase satiety after meals. Definitely it leads to a lower food intake.


Serotonin is strongly associated with food intake and carbohydrate and sugar selectivity. A serotoninanregender drug such as 5-HTP should therefore appetite suppressing and possibly reduce carbohydrate intake.

According to an early study, 5-HTP increased satiety rather than reducing appetite (15). The result is still a weight reduction as a result of lower calorie intake, which was spontaneously reduced by 38%. The participants ate 100 g of carbohydrates less a day due to the 5-HTP. The rather moderate dose was 8 mg / kg body weight.

A dose of 900 mg 5-HTP daily in another study reduced food intake by 42%. The appetite-suppressing effect resulted from an increased and early onset of satiety. Food selection changed as participants ate 50% less carbohydrates (12).

Due to the appetitive effect of 5-HTP, diabetic patients reduced calorie intake by 21% and carbohydrate consumption by 25% (13). The dosage used was 750 mg / day.

The use of a 5-HTP spray sprayed under the tongue resulted in a 15% decreased appetite but had no specific effect on carbohydrate intake (14). It should be noted that the uptake and dosing of 5-HTP differed significantly from the previously mentioned studies, which could be the reason for other results.

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5-HTP was used extensively in studies of depression in the 1980s and 1990s, but unfortunately these attempts were of poor methodological quality. Only one study from this period scientifically proven the efficiency of 5-HTP. A recent qualitative comparison between 5-HTP and the antidepressant fluoxetine in 2013 confirms that 5-HTP has the same effect as the antidepressant. Nevertheless, 5-HTP is not a drug that is standardized as a treatment for depression. Self-testing for mild depression should always be under the supervision of a physician. 5-HTP must not be combined with antidepressants as it may lead to serotonin syndrome. 5-HTP should be combined with L-tyrosine at high dose and for prolonged use, as otherwise dopamine levels in the brain may be lowered and adversely affect antidepressant therapy.

The ability of 5-HTP to reliably raise serotonin levels also made the substance interesting for use against depression. In fact, well over 100 studies on 5-HTP and depression have been conducted since the 1970s. An extensive meta-analysis of these studies by the Cochrane Collaboration in 2004 comes to a devastating judgment on the quality of the studies (16). Only two of the more than one hundred studies with a total of 64 participants have sufficient quality to be included in the meta-analysis (17, 18). Of these, a study has been conducted with the weaker drug L-tryptophan (18). The remainder is either weak in methodology or not placebo controlled.

For the remaining study, the authors come to the following conclusion:

The use of 5-HTP provides about 4 times as likely to relieve the symptoms of depression compared to placebo.

Despite the positive results, the final number of cases examined (64 participants) is too small to give a meaningful statement on the treatment of depression with 5-HTP or to recommend therapy with the drug.
A randomized, double-blind, placebo-controlled study from 2013 compared 5-HTP with the antidepressant fluoxetine. Both applications showed almost the same efficiency against depression from the 2nd week. Both treatments were effective until the end of the study (8 weeks). Patients were first given 150 mg 5-HTP daily divided into 3 doses of 50 mg each. Then the dose was increased from the second week to 300 mg daily and from the fourth week again to 400 mg daily. The side effects of 5-HTP were no stronger than with a standard dose of fluoxetine; some users had nausea, loss of appetite and headache (19).

High-dose 5-HTP over a longer period reduces the production of the neurotransmitter dopamine (20). 5-HTP uses the same enzyme pathways for conversion to serotonin that are also used by the body to produce dopamine and noradrenaline from L-tyrosine. Some scientists are of the opinion that 5-HTP should only be used in combination with L-dopa or L-tyrosine to achieve a balanced concentration of neurotransmitters in the brain (21). For many months high-dose 5-HTP could lead to a depletion of the dopamine stores in the brain.

Caution: Although the trend in science has proven the positive effect of 5-HTP in depression, self-treatment should only be given with the consent of the attending physician. Never use 5-HTP independently with antidepressants because it increases the risk of serotonin syndrome (see Dosage and Side Effects of 5-HTP).

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5-HTP can immediately reduce anxiety attacks in their strength and frequency.

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A dose of 200 mg L-5-hydroxytryptophan reduced the severity and number of panic attacks in a panic-triggering oxygen deprivation test (22). The same was confirmed by a double-blind, placebo-controlled trial in which the panic-inducing drug cholecystokinin was coadministered with 200 mg 5-HTP. The effect was more pronounced in women than in men, as they experienced fewer panic attacks (23).

Drowsiness in children is a sleep disorder characterized by fears and worries about going to bed. A relatively low 5-HTP dose of 2 mg / kg body weight daily was given just before bedtime to children aged 3 to 10 years. After 6 months of use, 83.9% of the children were free from sleep anxiety, compared to only 28.6% in the comparison group (24).


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People with sleep disorders could theoretically benefit from 5-HTP, but studies are missing that have focused only on this drug and sleep problems.

5-HTP is often advertised in connection with sleep problems. 5-HTP is converted into serotonin and serotonin is converted into the sleep hormone melatonin (25). Serotonin itself induces sleep and shortens the time it takes to fall asleep (sleep latency). Excessive or delayed serotonin stimulation may also increase alertness and inhibit sleep.

A dietary supplement composed of 5-HTP (Griffonia simplicifolia extract), Γ-aminobutyric acid (GABA), ginko biloba, valerian and other ingredients was studied in a randomized, double-blind, placebo-controlled study (26). Taking in the evening improved the following parameters in people with sleep problems:

Faster falling asleep (shortened sleep latency)
Slightly increased sleep duration
Rarer waking up during sleep
Shortened wake up time during the nightly wake-up phases
decreased tiredness after waking up in the morning
reduced snoring
Unfortunately, due to the use of several active ingredients, it can not be deduced on which aspects and to what extent the 5-HTP had a share.



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5-HTP is a generally safe drug. It must not be used with antidepressants (serotonin reuptake inhibitors, MAO inhibitors).


5-HTP has been used in more than one hundred clinical trials since the 1970’s, in a common dose range of 50 to 600 mg daily and more (up to 3250 mg in individual cases). So far, no adverse health effects of 5-HTP have been found (27).

Possible side effects include nausea and digestive problems. However, these can be avoided or reduced by multiple ingestion throughout the day (15, 28).

Under no circumstances should 5-HTP be used on its own initiative along with agents that significantly increase serotonin levels. Antidepressants (serotonin reuptake inhibitors and MAO inhibitors) should not be combined with 5-HTP unless it is prescribed by a doctor. The risk of experiencing serotonin syndrome (agitation, muscle twitching, sweating, and chills) is low, even in studies combining 5-HTP with antidepressants (29, 30). Nevertheless, caution and one’s own health should come first.

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5-HTP is a precursor to the neurotransmitter serotonin and is used for weight loss and depression. 5-HTP reaches the highest concentration in the blood for 1-2 hours after ingestion (31). It has a short half-life of 4.3 hours, that is, after this time, half of the drug is already degraded. Therefore, a more frequent intake is recommended with the single dose being kept lower (28). This also reduces the likelihood and severity of side effects such as nausea (32).
In studies where weight loss was a goal, 5-HTP was given three times a day, 30 minutes before meals. The single dose used varies between approximately 80 mg and 300 mg, depending on the study. The daily dose was 240 – 900 mg

It would be advisable to start with a low dose and to increase it only when necessary, because even an already low 5-HTP dosage achieved significant results in clinical studies.


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10. Abenhaim L, Moride Y, Brenot F, Rich S, Benichou J, Kurz X, et al. Appetite-suppressant drugs and the risk of primary pulmonary hypertension. International Primary Pulmonary Hypertension Study Group. The New England journal of medicine. 1996 Aug 29;335(9):609-16. PubMed PMID: 8692238.

11. James WP, Caterson ID, Coutinho W, Finer N, Van Gaal LF, Maggioni AP, et al. Effect of sibutramine on cardiovascular outcomes in overweight and obese subjects. The New England journal of medicine. 2010 Sep 2;363(10):905-17. PubMed PMID: 20818901.

12. Cangiano C, Ceci F, Cascino A, Del Ben M, Laviano A, Muscaritoli M, et al. Eating behavior and adherence to dietary prescriptions in obese adult subjects treated with 5-hydroxytryptophan. The American journal of clinical nutrition. 1992 Nov;56(5):863-7. PubMed PMID: 1384305.

13. Cangiano C, Laviano A, Del Ben M, Preziosa I, Angelico F, Cascino A, et al. Effects of oral 5-hydroxy-tryptophan on energy intake and macronutrient selection in non-insulin dependent diabetic patients. International journal of obesity and related metabolic disorders : journal of the International Association for the Study of Obesity. 1998 Jul;22(7):648-54. PubMed PMID: 9705024.

14. Rondanelli M, Klersy C, Iadarola P, Monteferrario F, Opizzi A. Satiety and amino-acid profile in overweight women after a new treatment using a natural plant extract sublingual spray formulation. International journal of obesity. 2009 Oct;33(10):1174-82. PubMed PMID: 19752879.

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18. Thomson J, Rankin H, Ashcroft GW, Yates CM, McQueen JK, Cummings SW. The treatment of depression in general practice: a comparison of L-tryptophan, amitriptyline, and a combination of L-tryptophan and amitriptyline with placebo. Psychological medicine. 1982 Nov;12(4):741-51. PubMed PMID: 7156248.

19. Jangid P, Malik P, Singh P, Sharma M, Gulia AK. Comparative study of efficacy of l-5-hydroxytryptophan and fluoxetine in patients presenting with first depressive episode. Asian journal of psychiatry. 2013 Feb;6(1):29-34. PubMed PMID: 23380314.

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21. Hinz M, Stein A, Uncini T. 5-HTP efficacy and contraindications. Neuropsychiatric disease and treatment. 2012;8:323-8. PubMed PMID: 22888252. Pubmed Central PMCID: 3415362.

22. Schruers K, van Diest R, Overbeek T, Griez E. Acute L-5-hydroxytryptophan administration inhibits carbon dioxide-induced panic in panic disorder patients. Psychiatry research. 2002 Dec 30;113(3):237-43. PubMed PMID: 12559480.

23. Maron E, Toru I, Vasar V, Shlik J. The effect of 5-hydroxytryptophan on cholecystokinin-4-induced panic attacks in healthy volunteers. Journal of psychopharmacology. 2004 Jun;18(2):194-9. PubMed PMID: 15260907.

24. Bruni O, Ferri R, Miano S, Verrillo E. L -5-Hydroxytryptophan treatment of sleep terrors in children. European journal of pediatrics. 2004 Jul;163(7):402-7. PubMed PMID: 15146330.

25. Klein DC, Berg GR, Weller J. Melatonin synthesis: adenosine 3′,5′-monophosphate and norepinephrine stimulate N-acetyltransferase. Science. 1970 May 22;168(3934):979-80. PubMed PMID: 4314985.

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27. Das YT, Bagchi M, Bagchi D, Preuss HG. Safety of 5-hydroxy-L-tryptophan. Toxicology letters. 2004 Apr 15;150(1):111-22. PubMed PMID: 15068828.

28. Westenberg HG, Gerritsen TW, Meijer BA, van Praag HM. Kinetics of l-5-hydroxytryptophan in healthy subjects. Psychiatry research. 1982 Dec;7(3):373-85. PubMed PMID: 6187038.

29. Kline N, Sacks W. Treatment of depression with an mao inhibitor followed by 5-HTP–an unfinished research project. Acta psychiatrica Scandinavica Supplementum. 1980;280:233-41. PubMed PMID: 6996430.

30. Alino JJ, Gutierrez JL, Iglesias ML. 5-Hydroxytryptophan (5-HTP) and a MAOI (nialamide) in the treatment of depressions. A double-blind controlled study. International pharmacopsychiatry. 1976;11(1):8-15. PubMed PMID: 770365.

31. Magnussen I, Van Woert MH. Human pharmacokinetics of long term 5-hydroxytryptophan combined with decarboxylase inhibitors. European journal of clinical pharmacology. 1982;23(1):81-6. PubMed PMID: 6182005.

32. van Hiele LJ. l-5-Hydroxytryptophan in depression: the first substitution therapy in psychiatry? The treatment of 99 out-patients with ‘therapy-resistant’ depressions. Neuropsychobiology. 1980;6(4):230-40. PubMed PMID: 6967194.