NOW Supplements 5-HTP 100 mg Review
#1 of 10 · Best overall✓ Label verified · Supplement Facts read Sep 7, 2026Real retailer photo, cut out. Label unedited.
Buy it. The sensible default first bottle of 5-HTP. A clean 100 mg Griffonia-sourced dose from a high-volume GMP brand at the best cost-per-capsule on the list (120 count, ~$0.18 each).
$22 / 120 veg capsules$0.18 / 100 mg capsule
Why It Scores 9.0 — And The Label Line Behind Each Number
Dose & form (enteric / cofactors)
30% of scoreA correct 100 mg starting dose in a clean single-ingredient veg capsule — exactly what a first-time 5-HTP buyer should take. Held below the top only because it's plain: no enteric coating to soften GI upset and no B6/C cofactors. For the default use case that simplicity is a feature, not a flaw.
- Active
- 100 mg 5-HTP (1 capsule)
- Cofactors
- None (single-ingredient)
Source & purity (Griffonia)
25% of scoreSourced from Griffonia simplicifolia seed extract — the standard clean source — in a vegan, Non-GMO capsule made without gluten or soy. NOW's high-volume, consistent supply chain is a genuine strength here; you're getting the same product batch after batch.
- Source
- Griffonia simplicifolia seed extract
Third-party testing
20% of scoreNOW's in-house QC labs and GMP-certified facilities are among the most consistent in mass-market supplements. Held below the top because this is house testing, not independent third-party certification — the bar Thorne (#3) clears and the one axis where NOW is bettered.
- Testing
- NOW in-house QC · GMP-certified facility
Value per day
15% of scoreAt roughly $0.18 per 100 mg capsule across a 120-count bottle, this is best-in-class value — the cheapest serious 100 mg option here, alongside Doctor's Best. It makes a multi-month trial inexpensive, which matters because 5-HTP needs a few weeks to judge.
- Count
- 120 veg capsules
- Cost
- $22 / bottle = ~$0.18 per 100 mg capsule
Real-world mood/sleep response
10% of scoreWell-tolerated by most and easy to stay consistent with. The one common complaint — mild nausea on an empty stomach, since it isn't enteric-coated — is usually solved by taking it with food. Felt mood/appetite/sleep response is individual and the evidence base is modest, so we keep this measured.
- More Specs
- Coating
- Not enteric-coated
- Best for
- A clean, reliable, low-cost first 5-HTP at the standard dose
- Safety
- Do not combine with SSRIs/SNRIs, MAOIs, triptans or other serotonergic drugs
Label verified. Every figure read from the Supplement Facts photo, Sep 7, 2026.
Marketing Claims Vs. Reality
100 mg 5-HTP from Griffonia simplicifolia.
The label dose and source are exactly as stated — 100 mg of 5-HTP extracted from Griffonia simplicifolia seed, the standard clean source. This is the standard starting strength and is correctly described.
Supports a positive mood and restful sleep.
There's a real but modest basis. 5-HTP is the direct serotonin precursor, and serotonin is the precursor to melatonin; the best mood evidence (Shaw 2002, PMID 12169147) found a signal of benefit but on a thin, under-powered study base. Reasonable as a supportive claim; overstated if read as a proven mood or sleep treatment.
Neurotransmitter support.
Mechanistically accurate — 5-HTP is converted to serotonin (5-HT), a neurotransmitter, in a single enzymatic step. The 'neurotransmitter support' framing describes the established mechanism, distinct from any specific clinical outcome claim.
Vegetarian/vegan, Non-GMO, made without gluten or soy.
Consistent with the product's labeling: a vegan capsule, Non-GMO, produced without gluten or soy. These are formulation facts and match the listing.
What Our Test Actually Found
The value is the headline — a 120-count bottle at the lowest cost per capsule
NOW's defining advantage here is price-per-serving: roughly $0.18 per 100 mg capsule across 120 capsules. Because 5-HTP needs a few weeks of consistent use before you can judge it, a cheap, large bottle lowers the cost of running a fair trial. Nothing else on the list undercuts it meaningfully at the standard 100 mg dose except Doctor's Best, which adds cofactors at a similar price.
It's plain on purpose — no enteric coating, no cofactors
This is single-ingredient 5-HTP: no enteric coating to bypass stomach acid, no vitamin B6/C to feed the conversion-to-serotonin pathway. For a default buyer that simplicity is fine, even preferable. But if you know 5-HTP upsets your stomach, Solaray's enteric coating (#6) is the targeted fix; if you want the cofactors, Doctor's Best (#2) bundles them. NOW deliberately competes on clean, cheap, and reliable rather than on features.
Testing is solid but in-house, not independently certified
NOW's in-house QC and GMP manufacturing are genuinely consistent — one reason it's a safe default. But it is house testing, not third-party certification. If 'I want an independent lab to confirm the label' is your priority, Thorne (#3) is the certified pick. For most buyers, NOW's track record is reassurance enough; for the testing-maximalist, it's the one place NOW is beaten.
Take it with food to head off the one common side effect
The most frequent 5-HTP complaint is mild nausea, and it shows up most on an empty stomach — which matters here because this capsule isn't enteric-coated. Taking it with a meal resolves it for most people. It's a small practical point, but it's the difference between sticking with 5-HTP and quitting it in week one over an upset stomach.
The safety caveat is the same for this bottle as for every 5-HTP
Nothing about NOW changes the core rule: 5-HTP raises serotonin and must not be combined with antidepressants (SSRIs/SNRIs), MAOIs, triptans, tramadol, or other serotonergic drugs without a clinician's sign-off, because of serotonin-syndrome risk. If you take any of those or have a medical condition, clear it with your doctor before starting. This isn't a NOW-specific warning — it's the price of admission for the whole category.
Full analysis: all pros & cons (8), buy if / skip if
- Best-in-class value — ~$0.18 per 100 mg capsule across a 120-count bottle
- Clean single-ingredient 100 mg dose at the standard starting strength
- Griffonia-sourced, vegan, Non-GMO, made without gluten or soy
- High-volume GMP brand with consistent batch-to-batch quality
- The simplest, most reliable default for a first 5-HTP
- No B6/C cofactors — Doctor's Best (#2) adds them for similar money
- Not enteric-coated — mild nausea possible on an empty stomach
- House/GMP testing only, not independently third-party certified
- You want to try 5-HTP and want the simplest, most reliable 100 mg default
- You value low cost per capsule and a large 120-count bottle
- You want a clean single-ingredient, Griffonia-sourced, vegan capsule
- You're not on any antidepressant or other serotonergic medication
- You want the B6/C cofactors built in — Doctor's Best (#2) adds them for similar money
- 5-HTP upsets your stomach — the enteric-coated Solaray (#6) is designed for that
- Independent third-party certification is your priority — Thorne (#3) is certified
A clean 100 mg Griffonia-sourced dose from a high-volume GMP brand at the best cost-per-capsule on the list (120 count, ~$0.18 each). No cofactors, no enteric coating, in-house testing — but for a standard-strength first 5-HTP you don't want to overthink, this is the one. Start at one capsule with food. Do NOT combine with antidepressants or other serotonergic drugs without a doctor's sign-off.
NOW Supplements 5-HTP 100 mg is the bottle we hand to anyone who just wants to try 5-HTP without studying the category. It's a clean, single-ingredient 100 mg dose of Griffonia simplicifolia-sourced 5-HTP — the standard starting strength — from a brand that ships at enormous volume with consistent GMP quality, at one of the lowest costs per capsule on the list. For a first 5-HTP, that combination of right dose, reliable manufacturing, and low price is exactly what you want. What it is not: enteric-coated, cofactored, or independently third-party certified. Those are real trade-offs that move other picks up or down for specific buyers, but none of them disqualifies NOW as the default. The one thing that applies to this bottle and every other 5-HTP on the market is the safety caveat: 5-HTP raises serotonin, so it must not be combined with antidepressants (SSRIs/SNRIs), MAOIs, triptans, or other serotonergic drugs without a clinician's sign-off. Take that seriously, start at one capsule with food, and here's the full breakdown.
The default first bottle of 5-HTP — clean, cheap, and reliable.
NOW Supplements 5-HTP 100 mg wins the top spot by being the thing most people actually need: a correct 100 mg Griffonia-sourced dose, single-ingredient, from a high-volume GMP brand, at the lowest cost per capsule on the list. There's nothing to study and little to get wrong — start at one capsule with food and give it a few weeks. Look elsewhere only for specific reasons. If you want the conversion cofactors, Doctor's Best (#2) adds B6 and C for similar money. If 5-HTP upsets your stomach, the enteric-coated Solaray (#6) is built for that. If independent third-party certification is your priority, Thorne (#3) is certified. And for everyone, the non-negotiable: do not combine 5-HTP with antidepressants or other serotonergic drugs without a clinician's sign-off — the serotonin-syndrome risk is real. For a clean, low-cost, standard-strength first 5-HTP, this is the bottle.
If This Doesn’t Fit — Try These
02Doctor's Best 5-HTP Enhanced
This is the pick when you want the conversion pathway fully fed without paying more for it.
05Natrol 5-HTP Time Release
Natrol is the cheapest way into 5-HTP, and the time-release tablet is a genuine point of difference — it spreads the 100 mg out instead of delivering it in one hit, which some people find gentler.
06Solaray 5-HTP Enteric Coated
If 5-HTP upsets your stomach — the most common complaint with it — Solaray is the targeted answer: it's the one product here that's actually enteric-coated, designed to carry the dose past stomach acid and release it lower down, and it throws in the B6 and C cofactors too.
Quick Answers
Can I take this with my antidepressant?
Not without a doctor's explicit sign-off — this is the single most important thing to get right. 5-HTP is a direct serotonin precursor, and combining it with an SSRI, SNRI, MAOI, triptan, tramadol, or other serotonergic drug can cause serotonin syndrome, a serious and occasionally life-threatening reaction (rapid heartbeat, agitation, confusion, shivering, fever). Authoritative sources including Memorial Sloan Kettering's integrative-medicine monograph and US Poison Control warn against the combination, and Drugs.com flags 5-HTP + SSRIs as a 'major' interaction. If you take any antidepressant or have a medical condition, talk to your prescriber before taking 5-HTP at all.
What dose should I start with, and when do I take it?
Start with one 100 mg capsule daily — that's the standard starting dose, and NOW delivers exactly that. Take it with food to reduce the mild nausea some people feel on an empty stomach. Many people take 5-HTP in the evening because serotonin is the precursor to melatonin, but if you're using it for daytime mood or appetite support, a with-a-meal timing is fine. Give it a few weeks before judging, and don't stack it higher than a single 100 mg dose without understanding the safety caveats first.
Does it actually work for mood?
The honest answer is 'there's a real but modest signal.' The best evidence is Shaw 2002, a Cochrane review (PMID 12169147): of 108 studies on 5-HTP/tryptophan for depression, only 2 met the quality bar, and pooled they showed benefit over placebo — but the authors stressed the evidence base was thin and under-powered. So 5-HTP is a reasonable low-cost experiment for mood support, not a proven antidepressant. If your mood symptoms are significant, that's a conversation with a clinician, not a supplement decision.
Why this over the Doctor's Best version with B6 and C?
Mostly preference. NOW is the cleanest single-ingredient 100 mg default at the lowest cost per capsule. Doctor's Best (#2) adds vitamin B6 and C — the cofactors your body uses to convert 5-HTP into serotonin — for roughly the same money, which is a small, sensible upgrade if you want the conversion pathway fully fed. Neither is enteric-coated and both are house-tested. If you want bare-bones simplicity, NOW; if you want the cofactors built in, Doctor's Best.
Will it upset my stomach?
It might, mildly — nausea is the most common 5-HTP side effect, especially on an empty stomach, and this NOW product is not enteric-coated. Taking it with food usually handles it. If you've had GI trouble with 5-HTP before, the enteric-coated Solaray (#6) is specifically designed to release the dose lower in the GI tract and may sit better. For most people, with-food dosing of the plain capsule is fine.
Sources & Further Reading
3 peer-reviewed sources, each linked to PubMed
- [1] Shaw 2002 (Cochrane) PMID 12169147 — Tryptophan and 5-hydroxytryptophan for depression. Of 108 studies on 5-HTP/tryptophan for depression, only 2 met the quality bar; pooled they showed benefit over placebo, but the authors stressed the evidence was insufficient. The honest anchor for the mood claim — a real signal on a thin base.
- [2] Cangiano 1992 PMID 1384305 — Eating behavior and adherence to dietary prescriptions in obese adult subjects treated with 5-hydroxytryptophan. Double-blind RCT, 20 obese subjects, 5-HTP 900 mg/day: significant weight loss, reduced carbohydrate intake, and early satiety. Behind the appetite/weight use case — small study, high dose.
- [3] Cangiano 1998 PMID 9705024 — Effects of oral 5-hydroxy-tryptophan on energy intake and macronutrient selection in non-insulin dependent diabetic patients. In overweight NIDDM patients, oral 5-HTP decreased energy intake and produced weight loss. Reinforces the appetite/satiety mechanism in a second small clinical population.
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