library.onepin.app/5-htp Peptide Education Library
Education only, not medical advice 21+ Every dose is an example to finalize with a licensed provider

OnePin Peptide Library · Cognitive & Mood

Cognitive & Mood 5-Hydroxytryptophan (Serotonin Precursor)

5-HTP

5-Hydroxytryptophan · Griffonia simplicifolia

5-Hydroxytryptophan (Serotonin Precursor)Mood / Sleep SupportDietary Supplement

5-HTP (5-Hydroxytryptophan) is the direct serotonin precursor, derived from L-tryptophan by tryptophan hydroxylase. Unlike L-tryptophan, 5-HTP does not require this rate-limiting enzyme and is converted to serotonin via aromatic amino acid decarboxylase. This makes 5-HTP a more direct serotonin booster than L-tryptophan supplementation.

Quick Start
Route
Oral capsule
Start low
50-100mg
Frequency
1-3x daily
Timing
Empty stomach (better absorption) but can cause nausea

Evening for sleep; morning for mood. Do NOT combine with SSRIs.

Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.

Tiered Protocols · lowest first
Quick Start
Conservative start
50-100mg · Oral capsule · 1-3x daily
Lowest starting point. Hold about a week to assess tolerance before stepping up.
50-100mg
1-3x daily
Standard
Serotonin & Sleep Support
100-200 mg · Oral · Daily
human study · Birdsall 1998 (Altern Med Rev 3(4):271-80)
100-200 mg
Daily
01

How it works

5-HTP bypasses the rate-limiting tryptophan hydroxylase step:

Direct Serotonin Precursor

AADC (aromatic amino acid decarboxylase) converts 5-HTP → serotonin. Both peripheral and CNS conversion occur.

Melatonin Pathway

Serotonin → N-acetyl-serotonin → melatonin (via pineal gland). Indirect sleep support.

Cofactor Need

AADC requires vitamin B6 (PLP). Some products include B6 to support conversion.

Peripheral vs CNS

Without carbidopa, much 5-HTP is converted peripherally to serotonin (which doesn't cross BBB). Carbidopa-co-administered 5-HTP enters CNS more efficiently. Most supplement use is without carbidopa - effects rely on small CNS fraction.

Serotonin Syndrome Risk

Combined with SSRIs, MAOIs, tramadol, MDMA, or other serotonergic drugs - serotonin excess can produce agitation, hyperthermia, autonomic instability, and rarely death. Single most important interaction.

02

What to expect

Early
Days 1–7

Days 1-7: subtle effects.

Mid
Weeks 2–4

Weeks 2-6: peak mood effect.

Later
Weeks 4–12

Cycle off after 12 weeks.

03

Evidence

HumanPresent
AnimalPresent
In-vitroPresent
19985-HTP efficacy and contamination · Birdsall TC, Alternative Medicine Review ↗review
2002Effects of 5-HTP and L-tryptophan on depression · Shaw K et al, Cochrane Database ↗review
04

Interactions & stacking

What's safe to combine, and what belongs in a separate pin.

Keep separate

05

Side effects & safety

Commonly reported

  • Nausea (most common)
  • Drowsiness
  • Mild GI

Less common & notes

  • Serotonin syndrome with serotonergic drugs (DO NOT COMBINE).
  • Vivid dreams.
  • Long-term: theoretical dopamine depletion via shared AADC pathway - cycle to avoid.
06

Pharmacokinetics

Illustrative plasma concentration · 24 h
Half-life
~2-7 hours plasma
Peak · Tmax
1-2 hours post-ingestion
Elimination
Hours plasma; cumulative neurotransmitter effects over weeks
Activity
Daily dosing for sustained effects

Storage. Capsule. Cool dry location.

07

Regulatory status

Dietary supplement (US, DSHEA). Banned in some EU jurisdictions.

Put it to work

Calculate, log & track

Open 5-HTP straight into OnePin with your vial and dose pre-filled, then let it handle the syringe math and remind you before the vial runs out.

Open 5-HTP in the app →

Go deeper

The guide & community

The complete 5-HTP walkthrough, real protocol discussion and coaching live inside the BlessUp community on Skool.

Join the community ↗
Open in app Community