NOW Foods L-Tryptophan 500 mg

NOW Foods · Capsule · 500 mg

Price/day

€0.32

Dose

500 mg

Servings/pack

Pack price

€18.90

Transparency Index

8.0/10

Recommended Solid serotonin precursor from a trusted brand. Good alternative to 5-HTP.

Rating breakdown

Evidence for ingredient 7.0/10

L-tryptophan as a serotonin/melatonin precursor has solid evidence for sleep improvement and mood support.

Value for money 7.0/10

€0.32/day for 500 mg pharmaceutical-grade L-tryptophan is fair.

Product quality 8.0/10

Pharmaceutical-grade purity, tested in NOW Foods' own analytics laboratory.

Label honesty 9.0/10

500 mg L-tryptophan clearly declared; clean ingredient list.

Third-party testing 8.0/10

NOW Foods operates its own analytics laboratory with over 16,000 tests per month.

Product Description

NOW Foods L-Tryptophan delivers 500 mg of this essential amino acid, which serves as a precursor to both serotonin and melatonin. Unlike 5-HTP, L-tryptophan is also used for protein synthesis and niacin production.

What We Like

500 mg per capsule — clinically relevant dose
NOW Foods quality standard with in-house laboratory
More versatile than 5-HTP (used in multiple metabolic pathways)

What We’re Missing

Absorption is inhibited by other amino acids — take on an empty stomach
60 capsules = approximately 2 months
Do not combine with SSRIs or MAO inhibitors

Usage Recommendation

1 capsule in the evening on an empty stomach, 30–60 minutes before sleep. Do not take with a protein-rich meal.

Other L-Tryptophan products

Jarrow Formulas L-Tryptophan 500 mg

6.9/10

Acceptable

Ingredient dossier

L-tryptophan is the precursor to serotonin and melatonin. Biologically plausible for sleep and mood, but direct supplementation effects remain limited and variable.

Read full dossier: L-Tryptophan →