NOW Foods L-Tryptophan 500mg (120 Veggie Caps)
by NOW Foods
"500mg L-tryptophan per capsule — the serotonin precursor for sleep and mood support with 120 capsules and 8,800+ reviews"
Overview
NOW L-Tryptophan 500mg provides the essential amino acid L-tryptophan, which is the direct precursor to serotonin (5-HT) and subsequently melatonin. The conversion pathway is: L-tryptophan → 5-HTP → serotonin → melatonin. Unlike 5-HTP (which bypasses the rate-limiting step), L-tryptophan allows the body to regulate serotonin production naturally through the enzyme tryptophan hydroxylase. Clinical studies show 1-2g of L-tryptophan before bed reduces sleep onset latency (time to fall asleep) by 50% in insomnia patients. L-tryptophan also supports mood, appetite regulation, and pain tolerance through the serotonergic system.
Key Ingredients
| Ingredient | Amount |
|---|---|
| L-Tryptophan | 500 mg |
1 ingredient linked to detailed encyclopedia profiles
Pros & Cons
What We Like
- 120 capsules
- 8,800+ reviews
- Natural serotonin precursor
- Body-regulated conversion
- Under $24
What Could Be Better
- Takes 30-60 min before bed
- May interact with SSRIs
- 500mg (may need 2 caps)
- Not as fast-acting as melatonin
Who Is This For?
Best For
- Sleep onset support
- Mood + sleep dual benefit
- Those wanting natural sleep aid
- Those who find melatonin too strong
Not Ideal For
- Those on SSRIs/MAOIs
- Those wanting immediate sleep
- Those wanting melatonin instead
- Those with carcinoid syndrome
Our Verdict
NOW L-Tryptophan 500mg is the natural sleep precursor — 500mg of the amino acid that becomes serotonin and then melatonin. Gentler than melatonin with mood benefits; avoid combining with SSRIs.
Alternatives to Consider
No direct alternatives listed for this product yet.