What is 5-HTP (5-Hydroxy-tryptophan) good for?

What is 5-HTP (5-Hydroxy-tryptophan) good for?

It's a well known and effective supplement for improving sleep, but what is 5-Hydroxy-tryptophan, commonly known as 5-HTP? How does it work, what are the risks and side effects, and how should it be taken?  Our expert nutritionists explain. 

What is 5-HTP

5-HTP is a natural chemical found in a seed from an African plant called Griffonia simplicifolia. Once ingested, the body converts 5-HTP into the hormone serotonin.

Serotonin is known as 'the happy hormone' because it helps to regulate our mood and appetite. Our bodies naturally produce serotonin from an amino acid called L-Tryptophan. 5-HTP is the mid-point in the synthesis of L-Tryptophan into serotonin, and is often taken by those whose bodies struggle to make the complete conversion. Discover 5 foods to improve your mood

L-Tryptophan is ingested from our diet. The probiotics in the gut convert L-Tryptophan into 5-HTP and then into serotonin. The serotonin is then transported into the brain on the back of insulin. There are some conditions associated with a low level of serotonin and supplementing with 5-HTP can help them.

Learn more in 'What are probiotics'.

Benefits of 5-HTP


Our sleep hormone, melatonin, is created from serotonin. Melatonin is the hormone that initiates sleep, and makes you feel sleepy when it gets dark in the evenings.

Melatonin is also needed to regulate your circadian rhythm which is your sleep–wake cycle. The body’s circadian rhythm can become out of balance due to factors such as travel, work patterns or an excess use of electronics late in the evening.

As a result, taking 5-HTP may help to reset the circadian rhythm and many people take supplements containing 5-HTP for better sleep. 

You may enjoy our research 'The Sleep Problem: 1 in 3 people suffer from poor sleep'.

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5-HTP is used for a variety of reasons, one of which is to uplift mood among those who do not have enough serotonin, or in people who need a boost. Low serotonin levels are associated with depression, anxiety and unstable moods. It's important to note 5-HTP should not be taken alongside prescribed medication for depression. 


One of the main functions of serotonin is to regulate our appetite. Serotonin blocks some receptors in the brain which trigger increased appetite. It also activates other neurons in the brain which work in a different way to regulate appetite.

As a result, 5-HTP may also be helpful to those looking to lose weight if excess hunger is a problem. One study found that 5-HTP supplements help to modulate food intake in individuals looking to lose weight. 

Read our nutritionists' advice for healthy weight loss

May help to improve fibromyalgia

Fibromyalgia is a health condition that causes pain in the muscles and bones. It also causes general muscle weakness and fatigue. Fibromyalgia is associated with low serotonin levels and supplementing with 5-HTP may help to raise serotonin levels which may reduce some of the symptoms.

How to take 5-HTP

How you take 5-HTP does depend on what you're looking to achieve through using it as a supplement. 

For sleep

For promoting sleep and to correct a circadian rhythm, 5-HTP should be taken around half an hour and up to 2 hours before bed. It is helpful to consume 5-HTP with a light carbohydrate snack to help with the absorption. This 30-120 minute gap before bed is important as it takes some time to convert into serotonin and then into melatonin.

For mood

For enhancing your mood, it is beneficial to split the dose of your 5-HTP over the course of the day, for example taking one with breakfast and another one around lunch or later with a snack. This way your body will have a constant supply of serotonin.

For appetite regulation

For appetite regulation, it is important to have a good dose of 5-HTP in the body before a meal. Taking 5-HTP 30 minutes before a meal allows the body time to convert it into serotonin to have its beneficial effects on appetite regulation.



Risks and side effects of 5-HTP

Like with many natural food supplements and remedies, there are a few potential side effects that can result when too much 5-HTP is taken.

Too much 5-HTP can result in serotonin levels spiking and may trigger symptoms such as anxiety and shivering. When taken in excessive amounts, 5-HTP can trigger blood abnormalities and muscle tenderness as well as drowsiness, digestive and muscular issues, and sexual dysfunction, in which case you should seek urgent medical advice.

5-HTP should not be taken if you are taking medication containing serotonin as this can lead to excess levels in the body. Medications containing Serotonin include antidepressants and some medications for Parkinson’s disease.

5-HTP is not recommended to individuals with Down syndrome. It should also not be taken for 2 weeks before a planned surgery as it may interfere with some of the anaesthetic medications that are commonly given during surgery.

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