hormone
Melatonin
Hormone regulating circadian rhythm. Supports sleep onset and jet lag recovery.
What it’s good for
Melatonin for Delayed Sleep-Wake Phase
Solid1 study · 1 supporting · 0 against
8 safety notes
A small dose hours before bed nudges your body clock earlier. That is a different job from the sleepy effect of a big dose.
Dose: 0.5 mg
Tested as: low-dose (0.5 mg fast-release) melatonin taken 1 hour before the patient's desired/target bedtime — NOT at the delayed bedtime the person has been naturally falling asleep at — on at least 5 nights per week, combined with behavioral sleep-wake scheduling (deliberately attempting sleep at the earlier desired time). The AASM guideline describes this generally as "strategically timed" melatonin, with timing set relative to the individual's circadian phase (e.g., dim-light melatonin onset) or desired bedtime rather than a fixed clock time — the timing, not a higher dose, is what does the work. The guideline notes that phase-shifting studies have not established any added benefit above 5 mg.
Melatonin for Insomnia
Mixed6 studies · 5 supporting · 1 against
8 safety notes
Tells your body it’s night. Best for jet lag or a shifted schedule.
Dose: 0.5–5 mg
Melatonin for Poor Sleep Quality
Mixed6 studies · 5 supporting · 1 against
8 safety notes
Acts on your body clock receptors to make sleep more efficient and deeper.
Dose: 1–3 mg
Tested as: 2 mg prolonged-release melatonin in adults aged 55 and older
Melatonin for Jet Lag
Mixed3 studies · 2 supporting · 1 against
8 safety notes
Melatonin is your body’s night signal. Taking it at bedtime where you land re-times your clock faster.
Dose: 0.5–5 mg
Tested as: melatonin 0.5–5 mg taken close to the target bedtime at the destination (roughly 10pm–midnight local time), once daily for several days after arrival, on flights crossing 5 or more time zones — benefit is clearest for eastward travel and grows with more zones crossed, and is weaker for westward flights or short (2–4 zone) trips. Doses of 0.5 mg and 5 mg reduced jet-lag symptoms similarly; 5 mg produced somewhat faster sleep onset and better sleep quality than 0.5 mg, but doses above 5 mg showed no added benefit. A 2 mg slow-release form was less effective than an equivalent fast-release dose, suggesting a short, higher peak works better than a smoothed-out one.
Melatonin for Chronic Inflammation
Evidence2 studies · 2 supporting · 0 against
8 safety notes
It is an antioxidant and influences immune signalling, which is the basis for the claim.
Dose: 3–10 mg
Tested as: oral melatonin 3-10 mg/day for weeks to months, studied mostly in people with an existing inflammatory or metabolic condition, not healthy adults
Melatonin for Low Mood
No Benefit1 study · 0 supporting · 1 against
8 safety notes
How it was tested: No improvement in depression or anxiety scores in postmenopausal women.
A disrupted body clock goes with low mood, which is the loose reasoning behind the claim.
Tested as: varies widely across small trials; no consistent dose/regimen studied specifically for low mood in a general population
Melatonin for Anxiety
No Benefit1 study · 0 supporting · 1 against
8 safety notes
How it was tested: No improvement in anxiety scores in postmenopausal women.
Meant to work through melatonin receptors and the brain’s calming system.
Tested as: no consistent trial evidence for generalized/chronic anxiety in a general population; the well-studied form is a single dose given before surgery for situational (procedural) anxiety, which is a different question — see needs_new_symptom
Melatonin for Chronic Fatigue
Not verified1 study · 0 supporting · 0 against
8 safety notes
Why it gets suggested: Combines melatonin’s antioxidant and body-clock effects with zinc. It was tested as a package.
Dose: 1 mg
Tested as: melatonin 1 mg plus zinc 10 mg, once daily for 16 weeks, in diagnosed ME/CFS patients — melatonin was never tested alone
Why we could not verify it: We read the research behind this and none of it concluded that it works for this. That is a finding about the papers, not a verdict that it does nothing.
Melatonin for Slow Recovery
Not verified8 safety notes
Why it gets suggested: Its antioxidant and anti-inflammatory activity is the theoretical basis for a recovery claim.
Tested as: no qualifying human RCTs of melatonin for general illness/injury/exercise recovery time were found
Why we could not verify it: We have not found research on this that we would stand behind. People take it for this, so the claim is here rather than hidden.
Melatonin for Frequent Colds
Not verified8 safety notes
Why it gets suggested: Melatonin influences immune activity in lab studies, which is the basis for the claim.
Tested as: no qualifying human RCTs of melatonin for cold frequency/incidence were found
Why we could not verify it: We have not found research on this that we would stand behind. People take it for this, so the claim is here rather than hidden.