How does Latisse (bimatoprost) make eyelashes grow longer?

Who doesn’t want long, luscious eyelashes? For years all we could do was paint them and stick on falsies, then Latisse landed on the market, promising to make your natural lashes gorgeous and doe-y. But how does it work? About lashes Lashes, like all hair, grows in a cycle, which involves 3 phases and takes 5-12 months.

Anagen - This is when the hair is growing and getting longer. This lasts 1-2 months, and the lash grows around 0.15 mm a day. In total, this means lashes will grow to about 9 mm long, with 2 mm staying under the skin. Catagen - Once the hair has finished growing, the growing base dies and form a club under the skin. Catagen lasts about 15 days. Telogen – This is when the lash just sits in the skin. Once anagen starts, the new hair pushes the old hair out of the follicle (exogen). Telogen lasts 4-9 months. In humans, individual hairs are in different stages of the cycle, so we don’t have a shedding period (like in dogs) where we lose lots of hair at once. About 41% of eyelashes are in the anagen phase at any time. What is Latisse? Latisse is a solution containing 0.03% bimatoprost, a synthetic prostamide. It was originally used as a treatment for ocular hypertension, when there’s too much fluid in the eyeball. Patients reported unusual eyelash growth, and so, a new drug was born! (This happens quite a lot – scientific discoveries are usually thanks to sheer luck!) How does bimatoprost work?  A lot of the exact mechanism of how bimatoprost works is currently unknown. What we do know: Bimatoprost doesn’t increase the number of lashes that can grow – at the moment, there’s no proven way of changing the number of hair follicles. Studies in mice suggest that it works by making lashes stay in the anagen (growing) phase for longer, which increases the lash growing time, and means longer lashes. Scalp hair grows for 6-8 years, which is why it’s so much longer! This also means new lashes form quicker, and old lashes fall out slower, so there are more visible lashes coming out at any time, which gives you denser lashes. Bimatoprost also increases the width of the bulb (the fat bit at the bottom), which makes the lash grow thicker. This effect is more noticeable with shorter hairs in the early stages of growth than longer lashes. The darkening of lashes treated with bimatoprost comes from stimulating the production of melanin, a chemical pigment that gives skin, hair and eyes their colour. Side effects The most common side effect is eye redness, which will happen if you put things near your eyes! Additionally, lashes aren’t the only things that have melanin – as well as making your lashes darker, bimatoprost can also make your skin and eyes darker. Skin darkening can be noticeable after a few months of use, and usually goes away after you stop using bimatoprost. Darkening of the irises – the coloured bit of the eye – was reported by 1.5% of people in a clinical trial when bimatoprost eyedrops are used, but when it was just used to paint the lashline, there were no reports of it happening. There’s obviously less contact with the eye when using bimatoprost only on the lashline, and a lot less is used than in an eyedrop (approximately one-twentieth of the amount). However, it’s a potentially permanent side effect, so light-eyed girls be careful! Have you used Latisse? Did it work for you? J L Cohen. Enhancing the growth of natural eyelashes: the mechanism of bimatoprost-induced eyelash growth. Dermatol Surg 2010, 36, 1361.


  1. says

    thanx for this! i was always wondering how it worked after watching the commercials. my other question is why do people feel the need to get a prescription because they don’t think they have enough lashes? i mean they are just eyelashes…

    • says

      I don’t think you need a prescription for Latisse, although you do for Lumigan, which is a lot cheaper and not intended for eyelashes (but is pretty much exactly the same stuff). I use it because I’m Asian and have tiny lashes! :)

  2. says

    Never heard of this stuff but I tried a product one that was supposed to help thickness and growth while you used it. I don’t think I gave it a chance so can’t testify to it. I have such fine hair that my brows have to be shadowed in and I never have to worry about hair removal. This might be worth trying for me…..

    • says

      I’ve heard that castor oil is pretty good for conditioning lashes and making them thicker, but I can’t find any info on it. It’s not expensive to buy though. Generic bimatoprost is much cheaper than Latisse, so make sure you look into that before you buy it!

    • says

      I actually want the side effects :P I have poopy brown eyes that are totally flat and boring, and I use eyeliner on my lashline – the darkening actually helps it blend in :) It worked out really well!

    • says

      The cheapest place seems to be All Day Chemist online – some people have had their credit details stolen there though, so it’s probably best to be careful and use a disposable credit card.

  3. says

    Oh god, I had visions of six year old two foot long eyelashes growing after I read this post. ‘No that’s absurd!’ I thought, until I read the first comment here. *terrified* ;)

    Anyway, nice post and great blog. I’m a bio phd (too? just started reading this blog) and love running into geeky science beauty/nail sites. Good stuff :)

    • says

      Haha! I don’t think it can extend the anagen phase indefinitely… at least it doesn’t on me, since my stubbly little eyelashes are only getting to NORMAL length with bimatoprost before dropping out *shakes fist*

      Thanks! I’m a synthetic organic (mainly peptide) chemist, with some pharmacology/physiology background (there are a lot of medicinal chemists in my department, so I end up at lots of lectures on drugs… additionally, I make a lot of bioactive compounds, although my focus is on making a class of chemical structures, rather than targeting a particular receptor). My biology background is pretty pathetic, really – I can deal with molecules small enough to have no tertiary structure, and I can deal with things larger than a cell, but I’m completely lost on anything in between!

    • says

      Oh, and I can deal with receptors and mechanisms of action, but in a handwavy kind of way – how it relates physically to the drug molecules is beyond me. To me, a receptor is a hole, and that’s all I can handle. >.<

  4. says

    Women with long eyelashes are really attractive. Seriously, it doesn’t matter if they are brunette or blonde; the eyes just say a lot about a woman’s physical beauty, and having long eyelashes improves it a lot.

  5. says

    Skin darkening is usually one of the side effects of bimatoprost. So before you start using it, ask yourself first if you’re willing to suffer these side effects. Once you start using it, it’s still better to consult your doctor should any of these side effects mentioned above arise. Yes it’s expected, but your body may react differently.

  6. says

    Latisse Generic consists of a major ingredient bimatoprost ophthalmic solution and it’s recommended to treat hypotrichosis.A condition wherein a person has inadequate or scanty growth of eyelashes is known as hypotrichosis.Latisse Generic helps in their growth thereby making them darker, longer and thicker.

  7. Stephanie says

    Hi, where did you get the Latisse? It doesn’t seem to be sold as an eyelash treatment in Australia, at least anywhere I’ve found!

  8. naturallashgrowth says

    Latisse is no doubt one of the best in the industry. The fda tag it has makes the consumer feel safe. Nice article, easy to understand the topic within minutes :)


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

CommentLuv badge