L-Tryptophan

Best for

Improve overall sleep quality

Likely real but unnoticeable · 1000–3000 mg/day for 1 weeks · 2 studies , n=220

13 papers · 3 claims · 33 outcomes scored · 3 positive

Outcomes

What l-tryptophan 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

Improve overall sleep quality Likely real but unnoticeable

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

2 RCTs n=220 1000–3000 mg 1 wk #7/37

25644221·31237183

trivial

2 RCTs n=220

1000–3000 mg

1 wk

#7 /37

Stay asleep through the night Likely real but unnoticeable

Fewer wake-ups and more unbroken hours of real rest.

1 RCT n=196 1000 mg 1 wk #7/15

31237183

trivial

1 RCT n=196

1000 mg

1 wk

#7 /15

Lift mood and reduce negativity Barely detectable

Fewer dark stretches and more spontaneous positive moments through the day.

1 RCT n=80 3000 mg 2 wk #4/6

25733537

trivial

1 RCT n=80

3000 mg

2 wk

#4 /6

Outcome	Effect	Evidence	Dose	Weeks	Rank
Improve overall sleep quality Likely real but unnoticeable	trivial	2 RCTs n=220	1000–3000 mg	1 wk	#7/37
Stay asleep through the night Likely real but unnoticeable	trivial	1 RCT n=196	1000 mg	1 wk	#7/15
Lift mood and reduce negativity Barely detectable	trivial	1 RCT n=80	3000 mg	2 wk	#4/6

Buy well

Recommended L-Tryptophan products

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

Chosen for adequate L-Tryptophan 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

serotonin_syndrome severe

eosinophilia-myalgia_syndrome severe

gastrointestinal discomfort (poor digestion / abdominal bloating) moderate

gastrointestinal disturbances mild

eosinophilia

myalgia

muscular_weakness

skin_thickening

Drug interactions

Antidepressants major increases toxicity

Co-studied with

Supplements that share evidence with l-tryptophan

Adenosine 1 shared outcome
Uridine 1 shared outcome

Sources

Generated August 14, 2026

L-Tryptophan

What l-tryptophan actually does, by outcome

Recommended L-Tryptophan products

Adverse events and known drug interactions

Supplements that share evidence with l-tryptophan

More evidence for L-Tryptophan

Stress: evidence map across 46 supplements

Sleep: evidence map across 37 supplements

Clinical trials found many null results for vitamin B

Ashwagandha

Chamomile

GABA

L-Tryptophan

Recommended L-Tryptophan products

More evidence for L-Tryptophan

NewStress: evidence map across 46 supplements

NewSleep: evidence map across 37 supplements

NewClinical trials found many null results for vitamin B

NewAshwagandha

NewChamomile

NewGABA

Stress: evidence map across 46 supplements

Sleep: evidence map across 37 supplements

Clinical trials found many null results for vitamin B

Ashwagandha

Chamomile

GABA