From Anirva, the maker of Sleep Harmony. This article is general information, not medical advice. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
If you have been reading about sleep, you may have come across 5-HTP. It sits on the path your body uses to make melatonin, the hormone that helps time your sleep. That makes it an interesting ingredient, and it also means safety deserves careful attention. Here we look at what 5-HTP is, what the sleep research found, how much is in Sleep Harmony, and what to know about medicines that affect serotonin.
In this article
Key Takeaways
- 5-HTP is a step on the way to melatonin. The body turns tryptophan into 5-HTP, then into serotonin and melatonin.
- Sleep research is limited but encouraging. In a 12-week trial in older adults, 100 mg a day helped poor sleepers fall asleep faster.
- Sleep Harmony contains 50 mg. This is half the amount used in that trial.
- Medicine interactions matter most. 5-HTP should not be combined with antidepressants or other medicines that raise serotonin.
- A doctor or pharmacist can help. If you take any medicines, checking with them before use is a good idea.
What Is 5-HTP?
5-HTP stands for 5-hydroxytryptophan. Your body makes it from tryptophan, an amino acid you get from food [1][2]. Supplements are made from the seeds of an African shrub called Griffonia simplicifolia [1].
From Tryptophan to Melatonin: How the Body Makes Its Sleep Hormone
Your body follows a series of steps to make melatonin. It starts with tryptophan from food. Tryptophan becomes 5-HTP, 5-HTP becomes serotonin, and serotonin becomes melatonin [1][2].
Cleveland Clinic explains that serotonin plays a role in sleep quality [2]. The brain also needs serotonin to make melatonin, the hormone that regulates the sleep-wake cycle [2].
This pathway explains why 5-HTP appears in sleep formulas. A pathway on its own does not show that a supplement improves sleep. For that, we look at the studies.
What Does the Research Show?
The research on 5-HTP and sleep is still growing, and there are few modern trials. Memorial Sloan Kettering Cancer Center lists sleep among the uses people take it for, and describes the evidence for anxiety and low mood as limited [1].
A 12-week trial in older adults
The clearest recent study was published in 2024. It included 30 older adults in Singapore, with an average age of 66 [3]. Half took 100 mg of 5-HTP a day for 12 weeks, and the others were in a control group [3].
Overall, 5-HTP had a favorable effect on some parts of sleep quality [3]. The benefit showed up mainly in people who slept poorly at the start. By week 12, the poor sleepers taking 5-HTP fell asleep faster [3]. People who already slept well showed no change [3]. The researchers also found changes in gut bacteria among the poor sleepers [3].
Study summary
| Study | People | Amount a Day | Length | Main Result |
|---|---|---|---|---|
| Sutanto et al., 2024 | 30 older adults | 100 mg | 12 weeks | Poor sleepers fell asleep faster by week 12; no change in good sleepers. |
How Much 5-HTP Is in Sleep Harmony Compared With the Studies?
| Source | 5-HTP a Day | Notes |
|---|---|---|
| Sleep Harmony (2 capsules) | 50 mg | From Griffonia simplicifolia seed |
| 12-week trial in older adults | 100 mg | 5-HTP alone |
5-HTP and Medicines That Affect Serotonin
This is the most important safety point for 5-HTP. Because it raises serotonin, it can add to the effect of other medicines and supplements that do the same.
Memorial Sloan Kettering advises against combining 5-HTP with antidepressants, including SSRIs, MAOIs and tricyclic antidepressants. It also advises against combining it with St. John's wort or SAMe [1]. It notes interactions with the antibiotic linezolid and with carbidopa [1]. Case reports describe serotonin syndrome in people taking 5-HTP [1].
Cleveland Clinic explains that serotonin syndrome happens when serotonin levels rise too much. Mild symptoms include shaking, sweating and confusion. Severe cases can be dangerous and need prompt medical care [2].
If you take any of these medicines or supplements, please talk with your doctor or pharmacist. This applies to 5-HTP and to products that contain it, including Sleep Harmony.
What the Research Does Not Show Yet
There are few modern sleep trials of 5-HTP, and the main one was small [3].
We found no trial of 5-HTP by itself at 50 mg a day for sleep.
We do not know how 5-HTP works together with melatonin in a formula, because the combination has not been tested.
Other Safety Notes
Memorial Sloan Kettering lists nausea, vomiting and diarrhea as the most common side effects. Headache, trouble sleeping and a racing heartbeat are less common [1].
In the past, some 5-HTP products contained impurities. Memorial Sloan Kettering notes a case where symptoms resolved once the product was replaced with one without these impurities [1]. This is one reason product quality matters.
5-HTP Is One Part of Sleep Harmony
Sleep Harmony combines melatonin, calming herbs and three probiotics in one formula. We chose ingredients that have each been studied for relaxation and sleep. 5-HTP is one of them.
Sleep Harmony has not been clinically tested as a finished product. For this reason, we cannot say how its ingredients work together. The study in this article tested 5-HTP by itself, and its results describe 5-HTP alone.
If you take Sleep Harmony, you are not relying on 5-HTP alone. It is one of 14 ingredients in each serving.
Good to Know
If You Are Deciding
If you take no medicines that affect serotonin, 5-HTP is one of several ingredients studied for sleep. If you do take such medicines, the safest step is to talk with your doctor before using it.
Good sleep habits remain the base. Cleveland Clinic suggests a steady sleep schedule, less caffeine and alcohol, and a cool, dark bedroom [5]. If you would like to try Sleep Harmony, the directions are two capsules 30 to 60 minutes before bedtime [4].
The Short Version
5-HTP is a step on the body's path from tryptophan to serotonin and melatonin. A small 12-week trial found that 100 mg a day helped poor sleepers fall asleep faster. Sleep Harmony contains 50 mg. Because 5-HTP raises serotonin, it should not be combined with antidepressants or similar products, so please check with your doctor if you take any medicines.
Frequently Asked Questions
Does 5-HTP help you sleep?
How much 5-HTP is used for sleep?
Is 5-HTP safe?
Can you take 5-HTP with antidepressants?
What is the difference between 5-HTP and melatonin?
How long does 5-HTP take to work for sleep?
Should I take 5-HTP in the morning or at night?
What are the side effects of 5-HTP?
References
- Memorial Sloan Kettering Cancer Center. About Herbs: 5-HTP. Last updated June 2, 2022. mskcc.org
- Cleveland Clinic. Serotonin: what is it, function and levels. Reviewed March 18, 2022. my.clevelandclinic.org
- Sutanto CN, Xia X, Heng CW, et al. The impact of 5-hydroxytryptophan supplementation on sleep quality and gut microbiota composition in older adults: a randomized controlled trial. Clin Nutr. 2024;43(3):593–602. PMID 38309227.
- Anirva. Sleep Harmony with Probiotics: Supplement Facts label and product page. anirva.com/products/sleep-harmony (accessed September 30, 2026).
- Umeda N (expert). Does magnesium help you sleep better? Cleveland Clinic Health Essentials. September 4, 2026. health.clevelandclinic.org
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