Strength of Evidence: High
Topical bimatoprost 0.03% is the most extensively studied and clinically validated treatment for eyelash hypotrichosis. It is the only eyelash growth agent supported by multiple large, multicentre, randomised, double-masked, vehicle-controlled trials using both clinician-rated and objective endpoints.
Evidence overview
High-quality RCTs demonstrate that topical bimatoprost:
- Significantly increases eyelash length, thickness, and darkness compared with vehicle
- Produces clinically meaningful improvement on validated Global Eyelash Assessment (GEA) scales
- Shows visible results typically emerging by 8 weeks, with peak improvement around 16 weeks
- Maintains benefit with continued use, with gradual return toward baseline following discontinuation
In a pivotal multicentre RCT, 78.1% of subjects treated with bimatoprost achieved at least a 1-grade improvement in eyelash prominence at 16 weeks, compared with 18.4% in the vehicle group.
Long-term randomised data (12 months) confirm sustained efficacy during ongoing treatment and demonstrate that benefits diminish several months after cessation, supporting the need for maintenance therapy.
Our Pharmacist’s Interpretation
The evidence supports topical bimatoprost 0.03% as the foundational, evidence-based treatment for eyelash hypotrichosis in adults. Its effects are biologically plausible, clinically meaningful, and consistently replicated across high-quality trials using validated outcome measures.
Unlike cosmetic lash serums, bimatoprost acts directly on follicular signalling pathways that prolong anagen and enhance follicle activity, explaining the magnitude and reliability of observed results.
Safety considerations (evidence-based)
Across RCTs, bimatoprost was generally well tolerated. Reported adverse effects were predominantly mild and local, including:
- Conjunctival hyperaemia
- Eyelid skin darkening (often reversible)
- Pruritus or irritation at the application site
Prostaglandin-related effects such as iris pigmentation change and periorbital tissue changes are well documented in ophthalmic use and remain important considerations in eligibility assessment, particularly in individuals with ocular conditions or prior eye surgery.
Key references
- Glaser DA et al. J Am Acad Dermatol. 2011.
Randomized, double-masked, vehicle-controlled multicentre trial of bimatoprost for eyelash hypotrichosis.
- Carruthers J et al. Br J Dermatol. 2015.
Long-term randomized controlled study evaluating efficacy, durability, and discontinuation effects.
- LATISSE® (bimatoprost 0.03%) Prescribing Information.
U.S. FDA. Clinical pharmacology, safety, and pivotal trial data.
