How to take 5-HTP: dosage, timing, duration

On 5-HTP packaging, 50–100 mg per capsule and a brief instruction "1 capsule per day" are usually indicated. However, scientific works used very different amounts and regimens, and the tolerability of the substance greatly depends on exactly how it is taken. The editors have gathered what is known about dosage, timing and duration, and explain which approaches allow side effects to be reduced.

Before you start: who should refrain

Any discussion of 5-HTP dosage should begin with the question of whether it can be taken at all. The supplement is contraindicated for people taking antidepressants, tramadol, triptans, linezolid and other serotonergic agents: the combination threatens serotonin syndrome (Boyer, Shannon, 2005).

5-HTP is not suitable for pregnant women, breastfeeding women, children, people with bipolar disorder, and also those awaiting a urine test for 5-HIAA. Caution is needed in diseases of the gastrointestinal tract and heart, and when taking drugs for Parkinson’s disease.

If the reason for interest in 5-HTP is depressed mood, anxiety or insomnia lasting for weeks, the correct first step is a doctor’s consultation. These conditions have many causes, and the supplement may only delay diagnosis.

For those who have passed this "filter," what follows are general principles. They do not replace a doctor’s recommendations or the instructions on the label of a specific product.

What amounts were studied in research

The range of 5-HTP amounts in clinical studies is wide and depends on the goal. In the work by Caruso and colleagues (1990) for fibromyalgia, 100 mg three times a day was used for 30 days. In appetite studies by the Cangiano group, significantly larger amounts were used — up to 900 mg per day, divided into three intakes before meals (Cangiano et al., 1992). In depression studies summarized in the reviews by Birdsall (1998) and Turner and colleagues (2006), daily amounts were most often 150–300 mg and higher.

It is important to understand that the high amounts in these works were used under medical supervision, in selected patients and for a limited time. Transferring them to independent use is incorrect. It was precisely at high amounts that nausea and other gastrointestinal symptoms most often arose.

Commercial products usually contain 50 or 100 mg per capsule, and manufacturers recommend 50–100 mg per day. This is the lower limit of what has been studied, and for independent use such a conservative amount is a reasonable benchmark.

A rule worth following: do not exceed the amount indicated by the manufacturer on the label without discussing it with a doctor. More does not mean better — with the amount, above all, the frequency of side effects rises.

A gradual start and division into doses

Since the most common side effects of 5-HTP — nausea and digestive disorders — depend on the single amount, the key strategy for minimizing them is a gradual start. It is advisable to begin with the smallest available amount, for example 50 mg, and assess the reaction over a few days.

The second principle is division. The short half-life of 5-HTP means that one large portion creates a sharp peak in concentration, whereas several smaller intakes give a more even profile. In clinical studies the daily amount was almost always divided into two or three intakes for precisely this reason.

The third is sensitivity to the body’s reaction. If nausea, diarrhea or headache persist, the amount should not be increased; on the contrary, it is better to return to a smaller one or stop taking it.

1. Start with the minimum amount (50 mg) once a day.
2. Assess tolerability over 3–5 days.
3. If necessary and within the label, divide the daily amount into 2 intakes.
4. With persistent side effects, reduce the amount or stop taking it.

You should not combine 5-HTP on your own with carbidopa or other decarboxylase inhibitors used in some medical studies. These are prescription drugs that change the pharmacology and risk profile.

Timing: food, sleep, training

Taking it with food reduces stomach irritation and for many people makes nausea less pronounced. Unlike tryptophan, 5-HTP depends less on competition with other amino acids for transport, so protein food does not reduce its effect as much.

If the goal is an effect on appetite, in the Cangiano studies 5-HTP was given about 30 minutes before main meals. For independent use this approach can be repeated with small amounts, remembering that part of the "satiety effect" may be associated with mild nausea.

People who take 5-HTP for sleep usually drink it in the evening, 30–60 minutes before bed, given serotonin’s role as a precursor of melatonin. There is little direct evidence of improved sleep from such a regimen, and in some people 5-HTP causes vivid dreams or restless sleep.

The editors do not recommend taking it before prolonged workouts: according to the serotonin hypothesis of central fatigue, enhancing serotonergic activity may worsen endurance (Meeusen et al., 2006).

Duration, breaks and monitoring

Most clinical studies of 5-HTP lasted from several weeks to several months. There are no data on the safety of continuous intake over many years, so for independent use it is logical to limit a course to a few weeks and to take breaks.

Long-term intake should be discussed with a doctor, especially if you notice that your condition worsens without the supplement. This may indicate a problem that requires diagnosis rather than a "need" for 5-HTP.

You should also watch for signs that require immediate discontinuation: agitation, tremor, fever, strong palpitations (possible serotonin syndrome), as well as muscle pain, rash, swelling or shortness of breath, which in rare cases have been linked to impurities in the product.

While taking 5-HTP, inform all doctors who prescribe you medications that you are taking it. This applies to the dentist and the surgeon too: some painkillers and anesthetics have serotonergic activity.

Editorial conclusions

The amounts of 5-HTP in studies ranged from 150–300 mg to 900 mg per day but were used under medical supervision. For independent use it is reasonable to follow the label, which usually means 50–100 mg per day.

A gradual start, division into several intakes and taking it with food are simple ways to reduce nausea and digestive disorders.

A course should be limited to a few weeks, 5-HTP should not be taken before prolonged workouts, and interactions with medications must be ruled out.

Related editorial materials: "Side effects of 5-HTP," "Who should not take 5-HTP" and "5-HTP: available forms and which to choose."

References

1. Birdsall TC. 5-Hydroxytryptophan: a clinically-effective serotonin precursor. Altern Med Rev. 1998;3(4):271–280.
2. Turner EH, Loftis JM, Blackwell AD. Serotonin a la carte: supplementation with the serotonin precursor 5-hydroxytryptophan. Pharmacol Ther. 2006;109(3):325–338.
3. Caruso I, Sarzi Puttini P, Cazzola M, Azzolini V. Double-blind study of 5-hydroxytryptophan versus placebo in the treatment of primary fibromyalgia syndrome. J Int Med Res. 1990;18(3):201–209.
4. Cangiano C, Ceci F, Cascino A, et al. Eating behavior and adherence to dietary prescriptions in obese adult subjects treated with 5-hydroxytryptophan. Am J Clin Nutr. 1992;56(5):863–867.
5. Boyer EW, Shannon M. The serotonin syndrome. N Engl J Med. 2005;352(11):1112–1120.
6. Meeusen R, Watson P, Hasegawa H, et al. Central fatigue: the serotonin hypothesis and beyond. Sports Med. 2006;36(10):881–909.