Bimatoprost

Action on the growth cycle

Bimatoprost is a prostaglandin analogue. Its effect on eyelashes is attributed in particular to a modification of their growth phase, with more active follicles and a prolonged growth phase. The exact mechanism is not fully understood. It therefore acts differently from a mascara, which deposits a visible material without modifying the activity of the follicle.

Results measured over several months

In the controlled trial published in 2012, approximately 78% of participants on bimatoprost achieved at least one grade improvement in overall eyelash appearance at sixteen weeks, compared to approximately 18% on vehicle alone. This number describes a clinical score, not a 78% increase in length. The relatively short duration and the selected population also limit what can be deduced for each user.

A benefit that requires maintenance

A follow-up study published in 2014 observed that improvements were maintained while treatment continued and gradually decreased after treatment was stopped. The product therefore does not permanently transform the eyelashes. This constraint counts in the decision: obtaining a satisfactory result also means accepting the duration, cost and monitoring necessary to maintain it.

Risks for the eyes and their contours

Bimatoprost may increase brown pigmentation in the iris, the colored part of the eye. This change may appear gradually and be permanent, even after stopping treatment. It should not be confused with darkening of the skin of the eyelids, which may improve after stopping. For aesthetic use, seeing your eyes darken over time is an undesirable effect to take into account before starting.

Possible effects also include itching, redness, irritation or dryness of the eyes. A reduction in fat around the eye can deepen the eyelid furrow and change the appearance of the eyes. These modifications were reported post-marketing, without making it possible to give a reliable frequency for use on eyelashes. They do not occur systematically, but can interfere with the desired aesthetic result.

The notices also mention a risk of worsening eye inflammation and cases of macular edema, swelling of the central area of the retina, especially in predisposed people. These precautions particularly concern certain eye histories or operations. The doctor must also take glaucoma treatments into account, because bimatoprost modifies eye pressure. The hygiene of the bottle and applicators also limits the risk of contamination and infection.

Eyelash growth is well demonstrated; our rating of 1/3 takes into account the benefit of the treatment in beautifying the eyes, with its constraints and possible undesirable effects. For normal eyelashes, we favor their gentle maintenance. A particular medical situation may warrant another decision, made with the professional who knows the person's eyes and history.