5-HTP (5-Hydroxytryptophan)

Reviewed by the HeyPsych Medical Review Board

Board-certified psychiatrists and mental health professionals

Published August 17, 2025•Updated February 20, 2026•Reviewed February 20, 2026

Indications

Primary Indications

Depression (mild to moderate, adjunctive use)InsomniaAnxietyFibromyalgiaAppetite suppression / weight management

Mechanism

5-HTP is the immediate precursor to serotonin (5-HT) and is converted via aromatic L-amino acid decarboxylase. Increased serotonin availability may improve mood, regulate appetite, and enhance sleep. Some serotonin is further metabolized to melatonin, supporting circadian rhythm.

Dosing

Adult Dosing

max: 400–500 mg/day (higher doses linked to adverse effects)

start: 50–100 mg orally, 1–3 times daily

titrate: Increase gradually based on tolerance

usual range: 100–300 mg/day

Dosage Forms

Capsules: 50 mg, 100 mg, 200 mg

Onset Duration

Mood and sleep effects may appear within 2–6 weeks of consistent use.

Adverse Effects

Common Side Effects

• nausea

• diarrhea

• drowsiness

• vivid dreams

⚠️ Serious Side Effects

serotonin syndrome (with serotonergic medications)
eosinophilia-myalgia syndrome (rare, linked to contaminated batches)

Warnings

Critical Safety Information

→Do not combine with SSRIs, SNRIs, MAOIs, or triptans due to risk of serotonin syndrome.
→Not regulated like prescription medications; quality of supplements varies.
→Caution in individuals with cardiovascular disease or GI disorders.

Interactions

With: SSRIs/SNRIs (e.g., sertraline, venlafaxine)

Risk: Serotonin syndrome

Action: Avoid combination

With: MAOIs

Risk: Hypertensive crisis or serotonin syndrome

Action: Contraindicated

With: Carbidopa

Risk: Increased risk of scleroderma-like illness

Action: Avoid combination

With: Alcohol or sedatives

Risk: Additive CNS depression

Action: Use caution

Monitoring

Signs of serotonin excess
GI side effects
Sleep quality

Special Populations

👶Pregnancy

Insufficient safety data; avoid use.

🤱Breastfeeding

Not recommended; excretion unknown.

👧Children & Adolescents (Under 18)

Safety not established.

👴Older Adults (65+)

Use lower doses; monitor closely.

Tapering

Not typically required, but gradual discontinuation is prudent to avoid sudden return of symptoms.

Clinical Notes

Quality control is a concern; third-party testing recommended.
Evidence strongest for depression and fibromyalgia but still limited.
May be more effective when combined with other supportive therapies (e.g., B vitamins, magnesium).

This treatment information is for educational purposes only. Treatment decisions should be made in consultation with qualified healthcare professionals based on individual circumstances, symptoms, and medical history. Do not attempt treatment without professional guidance.

Interested in this treatment?

This information is for educational purposes. Always consult with a qualified healthcare provider before starting any new treatment.

Locate Psychiatrists

5-HTP (5-Hydroxytryptophan)

Reviewed by the HeyPsych Medical Review Board

Board-certified psychiatrists and mental health professionals

Published August 17, 2025•Updated February 20, 2026•Reviewed February 20, 2026

Indications

Primary Indications

Depression (mild to moderate, adjunctive use)InsomniaAnxietyFibromyalgiaAppetite suppression / weight management

Mechanism

Dosing

Adult Dosing

max: 400–500 mg/day (higher doses linked to adverse effects)

start: 50–100 mg orally, 1–3 times daily

titrate: Increase gradually based on tolerance

usual range: 100–300 mg/day

Dosage Forms

Capsules: 50 mg, 100 mg, 200 mg

Onset Duration

Mood and sleep effects may appear within 2–6 weeks of consistent use.

Adverse Effects

Common Side Effects

• nausea

• diarrhea

• drowsiness

• vivid dreams

⚠️ Serious Side Effects

serotonin syndrome (with serotonergic medications)
eosinophilia-myalgia syndrome (rare, linked to contaminated batches)

Warnings

Critical Safety Information

→Do not combine with SSRIs, SNRIs, MAOIs, or triptans due to risk of serotonin syndrome.
→Not regulated like prescription medications; quality of supplements varies.
→Caution in individuals with cardiovascular disease or GI disorders.

Interactions

With: SSRIs/SNRIs (e.g., sertraline, venlafaxine)

Risk: Serotonin syndrome

Action: Avoid combination

With: MAOIs

Risk: Hypertensive crisis or serotonin syndrome

Action: Contraindicated

With: Carbidopa

Risk: Increased risk of scleroderma-like illness

Action: Avoid combination

With: Alcohol or sedatives

Risk: Additive CNS depression

Action: Use caution

Monitoring

Signs of serotonin excess
GI side effects
Sleep quality

Special Populations

👶Pregnancy

Insufficient safety data; avoid use.

🤱Breastfeeding

Not recommended; excretion unknown.

👧Children & Adolescents (Under 18)

Safety not established.

👴Older Adults (65+)

Use lower doses; monitor closely.

Tapering

Not typically required, but gradual discontinuation is prudent to avoid sudden return of symptoms.

Clinical Notes

Quality control is a concern; third-party testing recommended.
Evidence strongest for depression and fibromyalgia but still limited.
May be more effective when combined with other supportive therapies (e.g., B vitamins, magnesium).

Interested in this treatment?

This information is for educational purposes. Always consult with a qualified healthcare provider before starting any new treatment.

Locate Psychiatrists