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Lash Serum 101: Things No One Tells You

Growing Your Lashes Longer

So, you’ve finally decided to try a lash serum. Maybe you’ve always wanted super long lashes. Or you’re tired of using false lashes every time you go out with friends. Or maybe you’ve just seen way too many before and after shots of lashes from a certain skincare brand in your Facebook feed. But there are a few things you should know before you start using a lash serum. Or maybe a few things you should know about lash serum even if you’ve been using one for years.

Prostaglandins and analogues
Almost all lash serums work with a combination of vitamins, peptides and prostaglandin analogues. You can learn more about how prostaglandin analogues work in this post.

Lash serums aren’t pregnancy safe
So, because of various effects on both mom and baby, we don’t recommend prostaglandins during pregnancy. And while your lash serum has a very small amount and you use a very small amount, you likely won’t find a doctor who says it’s 100% safe. The study of lash serum safety would require a huge number of pregnant women, would be incredibly expensive, and likely would be unethical to perform. Personally, I stopped using my lash serum while pregnant and I recommend avoiding them when asked.

Give it time
It will probably take a minimum of 6 weeks to really see results from your lash serum, maybe even 12. For real.

Expect some irritation
Every lash serum that I’ve tried has given me itchy, irritated lash lines. I’ve found that cleansing my lash line each night with baby shampoo and minimizing my eye liner helps quite a bit. It usually starts about 4-5 weeks after starting lash serum, lasts about 2 weeks, and then goes away.

Note that with each new tube of lash serum does this to me, even if I’ve been using that brand for years. The very first tube is the worst and subsequent tubes aren’t as irritating, but it still happens.

You can use more than one
Each brand of lash serum has different ingredients in the mix to support your lashes and improve their growth. The only harm in doubling up is that you’ll likely have more irritation. If this is tolerable, if it a try! I’ve done well with a combination of Revitalash Advanced and R+F Lash Blast.

Your lashes won’t be the same
After lash serum my lashes are definitely longer and thicker, but they’re also a bit harder to manage. They are straighter, less likely to curl, and those longer lashes are also harder to get mascara on to, they wiggle around a lot.

I’ve found that the stiffer rubber pad in the Surratt Beauty Relevee Lash Curler really does make a big difference over other lash curlers (yes, including the Shu and Shiseido). My lashes curl much more easily and hold that curl all day.

As for mascara, I’m now obsessed with the Bobbi Brown Smokey Lash Mascara. Something about the wand deposits mascara onto my wiggly lashes more easily, and it is stiff enough to not let my lashes straighten out throughout the day.

Use it on your brows
The ingredients in lash serums don’t only work on your lashes, they also work on your eyebrows. You can use the same lash serum on your brows to help fill in any bare spots.

Many lash serums also come in a brow version, typically this is is just a gel version of the liquid lash serum. I’ve found that the brow version stays put a bit better on the brows, rather than dripping down like the lash version.

Mascara Tip Guide
Read more about mascara, mascara primers and lashes in my Mascara and Lashes Guide



  1. April 7, 2018 / 6:56 am

    I loved reading this today as I just started with Latisse! I am only 2-weeks in. So, I am excited to start seeing results soon. I do have a bit of irriation and have been experimenting with ways to distribute the liquid better as the brushes that came with the Rx are terrible! I am now using an ultra thin eyeliner brush instead of the disposable ones that come with the Latisse and then I was it every night and let it air dry in-between uses. It distributes the product much better (concentrates it to the actual lash line) and avoids getting more liquid onto the skin on the lids.

  2. Debbie Mecher
    April 7, 2018 / 7:11 am

    I loved using Revitalash which worked great on my lashes! Unfortunately, the product seemed to stopped working after I had been using it for a couple of years. Has anyone else had the same experience?

    • 15mins
      April 7, 2018 / 3:11 pm

      I did! I swapped to R+F Lash Boost, and I can swap back and forth with Revitalash, but it really did just stop working for me after about 2.5 years. It’s like my lashes were just tired of it.

  3. Kirsten
    April 9, 2018 / 3:30 am

    Is Latisse better than Revitalash and or Revitalash/R+F? I have short, fine, light brown lashes and there’s no way I could keep up with lash extension maintenance (I think). Even tho I have blue eyes, the rep at my derm was pretty clear on the iris color happening once during the trial and they implied it wasn’t actually Latisse. Eye definition makes such a huge difference for me, and I have to apply loads of mascara to have an impact (both Bobbi Brown and MUFE Smokey mascaras are great).

    • 15mins
      April 9, 2018 / 8:53 am

      So, I’ve heard from ophtho friends that they have seen iris darkening in some of their patients, though they watch closely for it and discontinue the Latisse if they see it.
      Latisse is the prescription version, so the prostaglandin analogue is stronger than the over the counter versions in Revitalash or R+F, but those versions also contain ingredients like peptides and antioxidants and I do think those help with lash growth as they help the skin in the area. Everyone’s lashes will respond differently to each product. If you’re worried at all about the iris thing happening, I would just pick one of the over the counter lash serums and go with it, if you aren’t getting the results you want after about 3 months I’d either add in or swap to a different one. 🙂

  4. Kirsten
    April 10, 2018 / 2:40 am

    Great to know about Latisse! I am more aware of how ingredients like peptides and antioxidants help the skin, and am fairly clueless on if/whether/how they help hair growth. I’ve often wondered if some companies even added them just because they sounded like or would be perceived as benefitial. Thanks!

    • 15mins
      April 10, 2018 / 8:21 am

      I asked a derm once if they actually do help hair growth and I guess the theory is that by supporting the skin and improving its overall health it is then able to support more hair growth 🙂

  5. Mimi
    January 24, 2019 / 5:31 pm

    I hope I found the right post! Is LashFood serum pregnancy safe?

    Water, Bergamot Peel Water, Lavender Flower Water, Citrus Orange Fruit Water, Butylene Gylcol , Paeonia Albiflora Root Extract, Panax Ginseng Root Extract, Trehalose, Aloe Barbadensis Leaf Juice, Hydrolyzed Rice Protein, Portulaca Oleracea Extract, Prunus Mume Fruit Extract, Xanthan Gum, Phenethyl Alcohol, Sorbic Acid, Hydrogenated Phosphatidylcholine, Potassium Sorbate, Arginine, Hydrolyzed Soy Protein, Adenosine, Lecithin, Coconut Fruit Juice.

    • 15mins
      January 24, 2019 / 6:02 pm

      It’s ok!

      • Mimi
        January 24, 2019 / 9:49 pm

        Thank you so much!

      • Eli
        March 19, 2019 / 8:47 am

        Is it also okay if you’re breastfeeding?

        • 15mins
          March 22, 2019 / 4:04 pm

          should be

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