Outcomes

What 5-htp actually does, by outcome

Each row is one outcome with effect size, evidence base, the dose that worked in trials, and time to first effect. Magnitude tiers come from native-unit MCID where available, Cohen's d otherwise.

Outcome Effect size Evidence Dose Weeks Rank

Lower day-to-day anxiety Not enough research

The background hum of worry that colors everything gets quieter.

2 RCTs n=30 100 mg 4–12 wk

2193835·40944161

trivial

2 RCTs n=30

100 mg

4–12 wk

—

Ease anxiety in older adults Not enough research

Quiets the health worries and body tension that build with age.

2 RCTs n=30 100 mg 4–12 wk

2193835·40944161

trivial

2 RCTs n=30

100 mg

4–12 wk

—

Reduce pre-competition anxiety Not enough research

Quiets the overthinking that hijacks execution right before you compete.

2 RCTs n=30 100 mg 4–12 wk

2193835·40944161

trivial

2 RCTs n=30

100 mg

4–12 wk

—

Ease depression symptoms Not enough research

Lowers the weight of sadness, low energy, and emotional numbness over weeks.

2 RCTs n=30 8–100 mg 5–12 wk

2468734·40944161

—

2 RCTs n=30

8–100 mg

5–12 wk

—

Ease winter depression symptoms Not enough research

Compensates for the sunlight deficit when days get short.

2 RCTs n=30 8–100 mg 5–12 wk

2468734·40944161

—

2 RCTs n=30

8–100 mg

5–12 wk

—

Ease depression tied to chronic pain Not enough research

When pain loosens its grip, mood follows.

2 RCTs n=30 8–100 mg 5–12 wk

2468734·40944161

—

2 RCTs n=30

8–100 mg

5–12 wk

—

Improve overall sleep quality Not enough research

Deeper, less interrupted nights that leave you recharged by morning.

1 RCT n=— 100 mg 4 wk

2193835

—

1 RCT n=—

100 mg

4 wk

—

Outcome	Effect	Evidence	Dose	Weeks	Rank
Lower day-to-day anxiety Not enough research	trivial	2 RCTs n=30	100 mg	4–12 wk	—
Ease anxiety in older adults Not enough research	trivial	2 RCTs n=30	100 mg	4–12 wk	—
Reduce pre-competition anxiety Not enough research	trivial	2 RCTs n=30	100 mg	4–12 wk	—
Ease depression symptoms Not enough research		2 RCTs n=30	8–100 mg	5–12 wk	—
Ease winter depression symptoms Not enough research		2 RCTs n=30	8–100 mg	5–12 wk	—
Ease depression tied to chronic pain Not enough research		2 RCTs n=30	8–100 mg	5–12 wk	—
Improve overall sleep quality Not enough research		1 RCT n=—	100 mg	4 wk	—

Buy well

Recommended 5-HTP products

Real products that dose 5-HTP where the research does, in a clean formulation, from brands we've audited. We only list ones we'd stand behind.

Chosen for adequate 5-HTP dosing vs. the studied range, a clean formulation (grade A–C), and independent brand-quality audits. Not sponsored.

Risk profile

Adverse events and known drug interactions

Safety events

seizures severe

hypoglycaemia severe

hyperthermia severe

vomiting moderate

Diarrhea (6 6-8 loose stools daily) with fecal incontinence moderate

Markedly increased urinary 5-hydroxyindole acetic acid (5-HIAA) excretion (393 µmol/24 h) moderate

elevated 24-h urine 5-hydroxyindoleacetic acid (5-HIAA) excretion moderate

hypomania moderate

Drug interactions

Antidepressants major increases effect

Nialamide major increases toxicity

Moclobemide major increases toxicity

Clomipramine major increases effect

Carbidopa moderate increases concentration

Antidepressants moderate unknown

Amitriptyline moderate increases effect

Sources

Generated August 14, 2026

5-HTP

What 5-htp actually does, by outcome

Recommended 5-HTP products

Adverse events and known drug interactions

More evidence for 5-HTP

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5-HTP

Recommended 5-HTP products

More evidence for 5-HTP

NewSeeds, Sleep, and Serotonin: How a West African vine met modern science

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Seeds, Sleep, and Serotonin: How a West African vine met modern science

Stress: evidence map across 46 supplements

Sleep: evidence map across 37 supplements

Ashwagandha

Bergamot (Citrus bergamia)

Caffeine