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5-HTP: benefits, dosage and side-effects

Find out all about 5-HTP, including what it does, the benefits to taking it and how much you might need

Written by Helen Foster on March 18, 2019 Reviewed by Dr Sarah Schenker on March 20, 2019


5-HTP is the shortened name for L-5 hydroxytryptophan.1 This is a compound our body creates from the amino acid tryptophan, found in foods such as turkey, salmon, seeds and eggs.2

What is 5-HTP and what does it do?

Our bodies use 5-HTP to make the neurotransmitter serotonin, which is involved with the regulation of mood, appetite and gut function.3 5-HTP does not occur naturally in any foods, which means we can’t get it from our diet. So, the idea of supplementing with 5-HTP is to remove the need to create it from tryptophan, which, in turn, is believed to raise serotonin levels in the body.4 Supplements of 5-HTP are often made with the seeds of an African shrub called Griffonia simplicifolia.5


What does 5-HTP do in the body?

5-HTP is involved in the production of serotonin. Regulating or raising levels of serotonin may have an impact on many conditions, including:

  • Depression – the evidence for 5-HTP’s ability to tackle depression is still unclear, but some studies have found a positive effect. For example, a 2013 trial of 70 patients experiencing their first episode of depression reported that 5-HTP had an ‘antidepressant effect’ on the subjects.6

  • Migraine – it’s still not known exactly what causes migraine, but one theory is that attacks are triggered by changes in serotonin levels in the brain.7 This has led some researchers to study the effects of 5-HTP on migraine – according to a classic study published in European Neurology in 1986, migraineurs who took 5-HTP experienced reduced severity and duration of attacks.8

  • Weight maintenance – one 1998 study conducted on 20 people discovered that those taking 5-HTP consumed fewer calories from carbohydrates and fat than those taking a placebo.9 In a more recent 2016 trial, researchers from Brunel University, London, backed up those findings using brain imaging scans, and suggested that 5-HTP alters our brain activity when we look at food – shifting our focus away from high-calorie and high-carbohydrate foods, towards healthier, higher protein foods.10
Studies have also found that 5-HTP can have a positive effect on sleep and fibromyalgia.11,12


How much 5-HTP is safe to take?

There is no recommended daily amount for 5-HTP, but studies into its effects have used amounts ranging from 50mg a day to 300mg. Do not take 5-HTP without seeing your GP first, especially before taking higher doses.13 You should not take 5-HTP supplements if you are also taking antidepressants or sleeping tablets, as this can be extremely dangerous.14


What are the side-effects of taking 5-HTP?

Because serotonin is also involved in gut activity, taking 5-HTP can lead to digestive issues such as heartburn, nausea or diarrhoea.15 This could be avoided if you start on a low dose, and then increase it gradually over a few weeks. Many experts advise against using 5-HTP to tackle depression. While low serotonin levels may be one cause, it’s not the only neurotransmitter involved – 5-HTP can actually reduce levels of other brain chemicals, such as dopamine and norepinephrine, low levels of which have also been linked to depression.16

If you feel like you may have depression, talk to your doctor before trying 5-HTP or any other remedies.

Shop Supplements Advice is for information only and should not replace medical care. Please check with your GP before trying any remedies.


1. Rachel Nall. Medical News Today. What are the health benefits of 5-HTP? 2. Claire Sissons. Medical News Today. How to boost serotonin and improve mood

3. As Source 1
4. As Source 1

5. Doug Bennett. Sciencing. What is Griffonia Simplicifolia? 6. Jangid P, et al. Comparative study of efficacy of l-5-hydroxytryptophan and fluoxetine in patients presenting with first depressive episode 7. Johns Hopkins Medicine. How a migraine happens 8. Titus F, et al. 5-Hydroxytryptophan versus methysergide in the prophylaxis of migraine. Randomized clinical trial 9. Cangiano C, et al. Effects of oral 5-hydroxy-tryptophan on energy intake and macronutrient selection in non-insulin dependent diabetic patients 10. Iannou S, Williams AL. Preliminary fMRI findings concerning the influence of 5-HTP on food selection 11. Shell W, et al. A randomized, placebo-controlled trial of an amino acid preparation on timing and quality of sleep 12. Caruso I, et al. Double-blind study of 5-hydroxytryptophan versus placebo in the treatment of primary fibromyalgia syndrome 13. Gavin Van De Walle. Healthline. 5 Science-Based Benefits of 5-HTP (plus dosage and side effects) 14. Serkalem Mekonnon. National Poison Capital Center. 5-HTP Safety Concerns 15. 5-HTP. MedlinePlus 16. Hinz M, Stein A, Uncini T. 5-HPT efficacy and contraindications