A prescription medicine that blocks a brain enzyme whose activity rises with age. Low doses repeatedly lengthened average lifespan in animals — one of the better-supported animal longevity compounds — but no direct human longevity evidence exists. In people it modestly improves Parkinson's movement and lifts mood, while often disrupting sleep and carrying serious interaction and blood-pressure risks. (Full Review)

Protocol

Dose

~1–5 mg/day oral

Low intermittent longevity dosing, well below the threshold for MAO-A inhibition

Timing

Morning

Aligns stimulant metabolites with daytime and minimizes insomnia

Frequency

Once-daily or intermittent

Every-other-day or few-times-weekly, exploiting irreversible enzyme inhibition

Time to effect

Longevity / Neuroprotection

Not perceivable

Cannot be felt by the individual; inferred only from animal data

Alertness & Mood

Days to a few weeks

Subjective effects on alertness or mood may appear within this window

Functional Effect

Persists days to weeks

MAO-B inhibition is irreversible, so the effect outlasts the short half-life

Benefits

High: Increased average lifespan in animal models

Medium: Improvement of Parkinsonian motor symptoms; antidepressant effect

Low: Neuroprotection and preserved cognitive/dopaminergic function

Speculative: Enhanced libido and sexual function; immune and general healthspan effects

Contraindications

Serotonergic antidepressants (SSRIs, SNRIs, tricyclics)

Other monoamine oxidase inhibitors

Meperidine and related opioids

Pheochromocytoma

Uncontrolled hypertension

Active psychosis or poorly controlled bipolar disorder

Pregnancy or breastfeeding

Key Interactions

Sympathomimetics and stimulants (pseudoephedrine, phenylephrine, amphetamines)

OTC cold and allergy products (dextromethorphan, decongestants)

Serotonergic/pressor supplements (5-HTP, L-Tryptophan, St. John's wort, high-dose L-Tyrosine or L-Phenylalanine, yohimbine)

Additive dopaminergic/stimulant supplements (Mucuna pruriens, high-dose caffeine)

Levodopa

Dietary tyramine (aged cheese, cured meats, fermented foods)

Risk & Side Effects

High: Insomnia and stimulant-like effects; neuropsychiatric adverse events

Medium: Hypertensive crisis at high doses; orthostatic hypotension and cardiovascular effects

Low: Dry mouth, nausea, and gastrointestinal effects; application-site reactions

Speculative: Long-term risks of amphetamine metabolites in healthy users; historically alleged increased mortality

Monitoring

Marker	Target	Why
Blood pressure (seated & standing)	~110–125 / 70–80 mmHg; <20 mmHg systolic drop on standing	Detects orthostatic hypotension and any pressor response
Resting heart rate	~50–70 bpm	Flags stimulant-related cardiovascular effects
Mood & anxiety screen (e.g., standardized questionnaire)	Stable, no worsening	Detects neuropsychiatric adverse events (agitation, anxiety)
Sleep quality	≥7 hours, good continuity	Insomnia is the most common side effect
Liver enzymes (ALT, AST)	ALT/AST ~10–30 U/L; conventional upper limit ~40 U/L	Drug is hepatically metabolized; baseline and periodic check is prudent

Cadence: Baseline, then at ~1–2 weeks and 4–6 weeks after starting or dose changes, then every 6–12 months thereafter

Qualitative Assessment

Energy and motivation levels
Mood and sense of wellbeing
Cognitive clarity and focus
Sleep quality and ease of falling asleep
Any agitation, anxiety, palpitations, or dizziness on standing

Selegiline for Health & Longevity

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment