Forskolin, a plant compound from Indian coleus root sold mainly as a fat-loss supplement, has thin human evidence: small, short fat-loss trials disagree, most run or supplied by extract makers, and benefits for long-term health remain unproven. Mild, dose-related diarrhea is the main known side effect; less certain but more serious concerns include rare liver injury, faster breakdown of common medicines, slower blood clotting and lower blood pressure. (Full Review)

Protocol

Standard body-composition protocol

250 mg extract twice daily

Root extract standardized to 10% forskolin (25 mg forskolin), for 12 weeks, as in all four trials

Lower-dose safety approach

Under 250 mg extract daily

Estimated lowest-diarrhea intake; 500 mg daily possibly acceptable

Time of day

30 minutes before meals

Trials dosed before the morning and evening meals; common practice shifts the second dose to midday

Time to effect

Body composition

12 weeks

When trials measured body-composition changes

Eye pressure

Within 1 week

Glaucoma add-on to prescribed eye drops; reversed within 40 days of stopping

Digestive effects

First 3 weeks

Loose stools appear early in use

Benefits

Medium: Body fat and body weight; asthma attack prevention; free testosterone in men; bone mass in men

Low: Eye pressure reduction in glaucoma; insulin sensitivity; blood lipids; heart output in heart failure; post-COVID-19 smell recovery

Speculative: Anticancer activity; liver fat reduction; memory protection

Contraindications

Pregnancy and breastfeeding

Polycystic kidney disease

Organ-transplant recipients on tacrolimus or cyclosporine

Bleeding disorders or surgery within 2 weeks

Active peptic ulcer

Low blood pressure (resting systolic below 90 mmHg) or symptomatic arrhythmia

Fatty liver disease or raised liver enzymes

Key Interactions

Topical glaucoma medications (timolol, latanoprost)

Theoretical (inferred from mechanism)

CYP3A4 substrates (atorvastatin, oral contraceptives)

Narrow-margin CYP3A4 drugs (tacrolimus, warfarin)

Acetaminophen (paracetamol)

Antiplatelet and anticoagulant drugs (aspirin, clopidogrel)

Over-the-counter NSAIDs (ibuprofen)

Blood-pressure-lowering drugs and nitrates (amlodipine, nitroglycerin)

Beta-agonists and phosphodiesterase-3/4 inhibitors (albuterol, theophylline)

Supplements that slow platelet clumping or blood clotting (fish oil, ginkgo)

Supplements that lower blood pressure (beetroot nitrate, magnesium)

Stimulant weight-loss supplements (caffeine, synephrine)

Diabetes medications (metformin, insulin)

Other enzyme-inducing supplements (St John's wort)

Risk & Side Effects

Low: Diarrhea and loose stools; liver injury; low blood pressure and rapid heart rate

Speculative: Accelerated drug clearance; bleeding tendency; kidney cyst growth; cellular senescence

Monitoring

Marker	Target	Why
ALT and AST	ALT 0–44 U/L, AST 0–40 U/L	Safety check: rise stops use
Blood pressure	Below 120/80 mmHg	Safety check: low readings stop use
Resting heart rate	60–100 beats per minute	Safety check: rise or palpitations stop use
Body weight and waist circumference	No established target; track change from own baseline	Expected to change
Body-fat percentage (DXA)	No established target; track change from own baseline	Expected to change
Fasting insulin and HOMA-IR	Fasting insulin 2.6–24.9 mU/L	Expected to change
Free testosterone (men)	52–280 pg/mL	Expected to change
Eye pressure (glaucoma users)	10–21 mmHg	Expected to change

Cadence: Blood pressure and heart rate daily for the first 2 weeks; liver enzymes at 4–8 weeks; body measurements, metabolic markers and eye pressure at 12 weeks; laboratory tests repeated every 6–12 months during continued use

Qualitative Assessment

Stool frequency and consistency
Palpitations, dizziness or light-headedness
Easy bruising or prolonged bleeding
Energy and fatigue
Appetite and fullness
Asthma symptoms (asthma users)
Sense of smell (post-COVID-19 users)

Forskolin for Health & Longevity

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment