Cognitive

Melatonin (Injectable)

Indoleamine · Pineal neurohormone · Synthetic

FDA · OTC SUPPLEMENT (ORAL)

Half-life

~50 minutes

Very short

minsdays

Route

SubQ injection

Evidence

Early human data

Risk

Standard

Overview

Known for

Sleep hormone. Injectable form provides more precise dosing and faster onset than oral. Regulates circadian rhythm, has antioxidant properties, and supports immune function. Injectable bypasses first-pass liver metabolism.

Mechanism

Natural sleep hormone produced by pineal gland. Injectable bypasses poor oral bioavailability for stronger/faster effect. Antioxidant, immune modulation, circadian regulation.

Key facts

Format
Lyophilized powder
Mechanism targets
Classification
Secondary
Supply & nature
Natural / Topping UpNatural
FDA category
OTC supplement (oral)

Evidence & standing

Evidence base
Early human data
Risk level
Standard
Best studies
5 references
  • Claustrat et al. (2005) Sleep Med Rev 9:11-24 — Comprehensive review
  • Oral melatonin: Schedule 4 (prescription-only) in Australia for most formulations. Circadin 2mg is Schedule 3 (pharmacist-only) for adults 55+.
  • Injectable form has minimal published human data
  • Oral melatonin NOT FDA APPROVED as drug but regulated as dietary supplement
  • Injectable bypasses first-pass metabolism — faster onset

Dosage & protocol

Typical dose
0.5-3mg
Research range
0.5–5 mg
Cycle
Daily (no cycling required)
Onset
0 days first effects
Full effect
0 days
Half-life
~40-60min
~40-60 minutes (oral) | ~20-30 minutes (injectable — faster clearance)
Protocol

0.5-3mg SubQ 30 min before bed. Start low — injectable is more potent than oral due to 100% bioavailability.

Time to effects

EARLY: 30-60 minutes

FULL: Single dose

On-demand sleep aid.

30-60 min: Drowsiness onset. Sleep induction.

Effects are per-dose. Injectable hits faster and harder than oral due to 100% bioavailability. No loading or accumulation needed.

For circadian rhythm resetting: consistent timing for 1-2 weeks establishes the new pattern.

Recommended vial
  • 10mg (only size)

At 1mg/night = 10 days ✓. At 3mg/night = ~3 days ✓. No shelf life issues.

Reference figures only

Dosing reflects published laboratory protocols and is not guidance for use in any living subject.

Safety

Reversibility
Fully Reversible
Side effects

Drowsiness (intended), vivid dreams, morning grogginess (dose too high or timed wrong), headache (rare)

Interactions

Sedatives/hypnotics (additive), blood thinners (melatonin has mild anticoagulant effect), immunosuppressants (melatonin is immunomodulatory), CYP1A2 substrates

Handle with research caution

  • Caution with sedatives, benzodiazepines, or other sleep aids (compounded sedation)
  • Caution with blood thinners (melatonin has mild anticoagulant properties)

Storage & handling

Lyophilised
12–24 months
room temp, per product label
Reconstituted
4–6 weeks
2–8°C