20% off £30

Use code:EXTRA

Positive woman doing exercise

5-HTP: benefits, dosage and side-effects

28 Jul 2021 • 2 min read


5-HTP, which is the shortened name for L-5 hydroxytryptophan, is a compound that’s made by the body.1

This compound is created by our bodies from the amino acid, tryptophan, which is found in foods, such as turkey, salmon, seeds and eggs.2

In this article, we talk you through all you need to know about 5-HTP, including what it does, the benefits of taking it and how much you might need of it.

What is 5-HTP and what does it do?

Our bodies use 5-HTP to make the neurotransmitter, serotonin, which contributes towards mood and appetite regulation, as well as influencing gut function.

5-HTP isn’t present in any foods, which means it isn’t something we can simply just get from our diet.

It is possible to take 5-HTP supplements – this removes the need for our bodies to create it from tryptophan, which is believed to raise serotonin levels in the body.

5-HTP supplements (more on them below) tend to be made from the seeds of an African shrub called Griffonia simplicifolia.3

5-HTP benefits and uses

As we’ve just mentioned up above, 5-HTP is involved in the production of serotonin.

It’s thought regulating the amount of serotonin in our system may have an impact on many conditions, including:

  1. Depression

The evidence for 5-HTP’s ability to tackle depression is still unclear, but some studies have found it to have a positive effect.

For example, a 2013 trial of 70 patients, who were experiencing their first episode of depression, concluded 5-HTP did have an ‘antidepressant effect’ on the subjects.4

  1. Migraines

It’s still not known exactly what causes migraines, but one theory is they’re triggered by changes in serotonin levels within the brain.5

This has led to some researchers studying the effects of 5-HTP on migraines – according to one classic study published in European Neurology in 1986, migraineurs who took 5-HTP experienced reduced severity and duration of attacks.6

For more on migraines, check out this article, ‘The ultimate guide to migraines.’

  1. Weight maintenance

One 1998 study involving 20 people found that people who were taking 5-HTP consumed fewer calories from carbohydrates and fat than those taking a placebo.7

In a more recent 2016 trial, researchers from Brunel University backed up these findings.

Using brain imaging scans, their study suggested 5-HTP alters our brain activity when we look at food, shifting our focus away from high-calorie and high-carbohydrate foods, and towards healthier and higher protein foods.8

  1. Anxiety

It’s believed taking 5-HTP may help ease anxiety. However, more research is required to prove this.

Early studies have found that taking 25 to 150 mg of 5-HTP a day, alongside carbidopa, appears to reduce anxiety symptoms.

However, other early research has shown taking higher doses of 5-HTP, 225mg a day or more, may make anxiety worse.

More research into the link between 5-HTP and anxiety is therefore required.9

  1. Sleep

5-HTP produces serotonin, which can be converted into the hormone, melatonin.

It’s this particular hormone that helps regulate our sleep and, because of this, it’s thought that taking 5-HTP for sleep can potentially increase how much melatonin our bodies produce.10

  1. Fibromyalgia

Studies have also found that 5-HTP can have a positive effect on fibromyalgia.

This is due to the fact low serotonin levels have been linked to potentially contributing to the condition, which causes muscle and bone pain and weakness.

Initial studies have found 5-HTP may improve symptoms of fibromyalgia due to its ability to increase serotonin levels.11


5-HTP helps our bodies produce serotonin.

Because of this, it’s thought it may help with several serotonin-related issues and health conditions, such as migraines, depression and anxiety.

How much 5-HTP is safe to take?

There’s no recommended daily amount for 5-HTP, but studies on its impact on the human body have involved amounts, ranging from 50mg a day to 300mg.

If you’re considering taking 5-HTP, don’t do it unless you’ve seen your GP first, especially if you’re planning on taking higher doses.12

You should not take 5-HTP supplements if you are also taking antidepressants or sleeping tablets, as this can be extremely dangerous.13

5-HTP side effects and risks

So 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 diarrhea.14 

This could be avoided if you start on a low dose, and then increase it gradually over a few weeks.15

Other side effects include:

  • Stomach pains
  • Drowsiness
  • Sexual problems
  • Muscle problems

What are the risks associated with taking 5-HTP?

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 believe you have depression, talk to your doctor first before trying 5-HTP or any other remedies.

They will be able to advise you on whether or not 5-HTP is the best solution for you and, if it is, the recommended dosage, depending on your symptoms.

Other risks include

  • 5-HTP and pregnant or breastfeeding women - there isn't enough reliable information at present to know if 5-HTP is safe to use when pregnant or breast-feeding. Not taking it is therefore the safest option
  • 5-HTP and children – it’s believed that it’s safe for children, infants to 12-year-olds, to take up to 5mg/kg of 5-HTP a day. However, there is a risk they might develop eosinophilia-myalgia syndrome, which is a serious condition that causes extreme muscle tenderness and blood abnormalities
  • H-HTP and surgery – due to 5-HTP’s ability to impact serotonin levels, it’s best to stop taking 5-HTP two weeks before surgery, especially if the medication you’re given during surgery impacts serotonin levels too. Taking 5-HTP pre-surgery might result in there being too much serotonin in the brain, which can lead to serious side effects, including heart problems, shivering and anxiety


As is the case with taking most supplements, there are side effects linked to taking 5-HTP.

The side effects include digestive issues, such as heartburn and diarrhea.

There are also risks associated to taking it for depression, before surgery and if you are pregnant or breastfeeding.

Is 5-HTP safe for everyone?

5-HTP tablets aren’t recommended for everybody. If you have a high blood pressure or diabetes, you should speak to your doctor first.17

And if you’re taking antidepressants, have liver disease, are pregnant or breastfeeding, it’s not advisable for you to take it.

Is 5-HTP bad for your liver?

Taking 5-HTP tablets can potentially mean you’re at risk (a small risk) of developing liver toxicity. L-tryptophan, which is closely linked to 5-HTP and has been associated with liver failure.18

While 5-HTP may not categorically cause this problem, its connections with L-tryptophan means it’s best you check with your doctor first if you do intend to take it.

This is particularly important if you currently have or have had liver problems in the past.


5-HTP isn’t something everybody can take. If you are on anti-depressants, have liver disease or are pregnant or breastfeeding, you shouldn’t take it.

The advice in this article is for information only and should not replace medical care. Please check with your GP or healthcare professional before trying any supplements, treatments or remedies. Food supplements must not be used as a substitute for a varied and balanced diet and a healthy lifestyle.

Last updated: 28 July 2021



Author: Donia HilalNutritionist

Joined Holland & Barrett: Jan 2018

Bsc in Nutrition, Registered Associate Nutritionist and Certification in Pre and Post Natal Nutrition

Donia started her career as a freelance nutritionist, later she joined Nestle as their Market Nutritionist to help support their healthier product range, before joining the team at Holland & Barrett in January 2018.

Donia has over 6 years experience as a Nutritionist and also works with clients on a one to one basis to support their goals which include weight loss, prenatal and postnatal nutrition and children’s health.

Read more
  • Visa
  • MasterCard
  • PayPal
  • AmericanExpress
  • ApplePay
  • ClearPay
  • AliPay
  • Instagram
  • Pinterest
  • Facebook
  • Twitter
Copyright © Holland & Barrett Retail Limited, 2023. All rights reserved. hollandandbarrett.com is a trading name of Holland & Barrett Retail Limited,. Registered office: Samuel Ryder House, Barling Way, Nuneaton, Warwickshire CV10 7RH. Registered in England: company no. 2758955. Registered VAT no. 211727395.