L-Tryptophan
Also known as: tryptophan, L-Trp
An essential amino acid and the dietary precursor to serotonin and melatonin. Supplemental tryptophan is used in sleep and mood formulas, and a systematic review of trials at roughly 0.14–3 g/day found modest benefits for mood in healthy adults. Because it raises serotonin synthesis, it carries a drug-interaction caution for anyone on serotonergic medication and should not be combined with 5-HTP or St. John's Wort at meaningful doses.
Research summary
Converted to 5-HTP and then serotonin, and onward to melatonin in the pineal gland.
Dosage
Daily amounts, of compound.
| Lowest studied | Typical range | Highest studied | Upper limit |
|---|---|---|---|
| 500 mg | 500–2,000 mg | 3,000 mg | — |
Mood and sleep trials used about 0.14–3 g/day; 500–2,000 mg taken 30–60 minutes before bed is the consumer norm. Taking it with a small carbohydrate serving and away from other large amino acids increases brain uptake, since tryptophan competes with other large neutral amino acids at the blood-brain barrier.
Source material: fermentation-derived
Format suitability
- Capsule
- Powder
- Tablet
- Softgel
- Gummy
- Liquid
Bitter and poorly soluble; capsules are the usual format. 1 g needs about two size-00 capsules.
Formulation notes
Do not stack with 5-HTP or St. John's Wort. Label cautions are standard for users of SSRIs, MAOIs, and other serotonergic drugs. Vitamin B6 and magnesium are frequent cofactor pairings in sleep formulas.
- Notable drug interactions
Sources
Related ingredients
Ashwagandha Root Extract (KSM-66)
BotanicalA branded, root-only ashwagandha extract standardized to at least 5% withanolides.
Typical: 300–600 mg
Ashwagandha Root Extract (≥5% Withanolides)
BotanicalA generic, non-branded ashwagandha root extract standardized to at least 5% withanolides.
Typical: 300–600 mg
L-Theanine
Amino acidAn amino acid found naturally in green tea that promotes a calm, focused state without sedation.
Typical: 100–200 mg
5-HTP (5-Hydroxytryptophan)
Amino acidThe immediate precursor to serotonin, extracted commercially from Griffonia simplicifolia seeds.
Typical: 50–300 mg
Chamomile Flower Extract
BotanicalAn extract of German chamomile flowers standardized to apigenin, the flavone behind much of its calming reputation.
Typical: 220–1,100 mg