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For many, popping on some mascara is a daily routine. It’s a beauty staple, but how much do you really know about what’s inside your favorite tube?

If you check the packaging, you might see a list of lengthy, unpronounceable names.

You may have heard the rumor that mascara contains bat poop, or that there may be potentially harmful ingredients lurking inside.

Here’s what the experts have to say about what’s really inside mascara.

Modern mascara is made of a few essential ingredients:

  • pigment to darken
  • polymer to coat
  • preservatives to keep it fresh
  • thickening agents to give it texture

“Typically, mascaras get their dark color from a carbon black or iron oxide pigment,” says Sophie Hardcastle, a senior aesthetic therapist at Coppergate Clinic.

Then there’s waterproof mascara, which has a few extras like:

  • emollients, like isododecane
  • silicones, like cyclopentasiloxane
  • waxes, like beeswax or candelilla wax

Manufacturers include these ingredients to achieve the desired texture, Hardcastle explains. She also notes that waterproof mascaras have water much further down on the ingredients list than regular mascaras.

According to Hardcastle, preservatives are included to give your mascara a little extra shelf-life.

What was mascara made of in the past?

People have been wearing mascara for centuries.

It’s believed that the ancient Egyptians used burned ashes and kohl to darken their lashes, mixing it with honey to make it sticky.

Modern mascara can be traced back to the early 1900s. Some say it was French chemist Eugene Rimmel that first invented industrial non-toxic mascara in 1913. Others claim it was beauty entrepreneur Max Factor.

Either way, formulas have come a long way since then.

“The safety of using mascara has improved greatly since the 1930s, when the ingredients used to darken lashes were turpentine, kohl, and aniline,” Hardcastle says.

Some consumers even experienced blindness as a result.

“Understandably, the ingredients that manufacturers can include in their products now are much more closely regulated,” Hardcastle adds.

Mascara ingredients are much safer than they used to be. Still, there’s a widely-circulated belief that mascara contains bat poop.

There’s no truth to it. This misconception comes down to a terminology mix-up.

“The myth that mascara contains bat feces stems from the similarity of two words: guano and guanine,” Hardcastle says.

Guano refers to bat feces, which isn’t used in cosmetics.

“Guanine, however, is used in the cosmetics industry as a colorant and an opacifying agent,” Hardcastle says.

Guanine is sourced from fish scales, meaning some mascaras do contain an animal derivative.

Guanine is typically added to mascaras to give them a glossy, iridescent quality.

However, it’s becoming more common for brands to opt for the vegan chemical bismuth oxychloride instead.

There’s no single answer to this question. In fact, it comes down to your individual preferences and needs.

“If your lashes are dry, look for mascaras that include nourishing oils, such as castor oil and jojoba oil,” Hardcastle advises.

If it’s a curl or extra volume you’re after, choose a thicker formula.

“The volume and lash curling ability of mascaras mostly come from the inclusion of waxes (such as beeswax, paraffin, or carnauba) in their formulations, making the mascara thicker,” Hardcastle explains.

For dry lashes:

  • castor oil
  • jojoba oil

For thicker lashes:

  • beeswax
  • paraffin
  • carnauba

As for what you should avoid, it’s advisable to steer clear of the now lesser-used thimerosal.

“Although it can still be found in a few mascaras, this preservative can cause conjunctivitis and eyelid dermatitis,” Hardcastle says.

She also warns against using petroleum or propylene glycol-based formulas, as they can trigger an allergic reaction in some people.

Make sure to dispose of your mascaras every 3 to 6 months. After that, they may harbor bacteria that can lead to infection.

If chucking a full tube of mascara after only a few short months of use feels like a waste, consider buying smaller sample size tubes. They’re cheaper, and you’re more likely to use them up before they go out of date.

It’s best to remove your mascara before you go to bed.

Sleeping in mascara can cause discoloration around the eyes, dehydration, and blocked pores, explains Elizabeth Hawkes, a consultant oculoplastic and ophthalmic surgeon at the Cadogan Clinic.

“Additionally, not removing eye makeup can increase the risk of infection and eye irritation due to the accumulation of dirt and bacteria as well as the chemicals used in eye makeup products,” Hawkes adds.

To remove your mascara effectively, she recommends a gentle approach.

“Aggressive eye makeup removal can accelerate the eye-aging process,” Hawkes says. “That’s why regular eyelid hygiene using minimal pressure is advised.”

Follow these steps:

  1. Soak a cotton wool pad in your choice of makeup remover.
  2. Place the pad over your eye for a few seconds.
  3. Rub gently from the inner eye toward the ear.
  4. Repeat until all mascara is removed.

When it’s waterproof

Waterproof formulas can be a little more difficult to remove.

Hardcastle recommends using an oil-based makeup remover to avoid damage to your lashes and the sensitive area around your eyes.

When it’s fiber-based

If you’re removing fiber mascara, Hawkes says it’s best to use a little more makeup remover than usual to ensure you remove all the fibers. Again, a gentle motion is best.

The good news is that it’s mostly safe to wear mascara every day as long as proper care is taken.

“In most cases, it’s fine to wear mascara regularly if you remove it properly at the end of the day,” Hardcastle says.

Just keep an eye out for any reactions.

“If your eyes are particularly sensitive or you notice irritation, you may want to limit how often you wear mascara or swap your current product out for one with different ingredients.”

Ultimately, the best mascara to use comes down to personal preference.

Hardcastle recommends the RevitaLash Double-Ended Volume Set.

“This is a 2-in-1 primer and mascara that is not only cruelty-free, but also oil-free, fragrance-free, and clinically tested,” she explains.

She also recommends choosing a mascara that’s water-resistant, not waterproof.

“This is much easier to remove and avoids damage to the delicate eye area,” Hardcastle adds.

Saffron Hughes, makeup artist at FalseEyelashes.co.uk, is a big fan of fiber mascaras. These contain tiny fibers typically made of rayon or silk that are brushed onto the lashes to add thickness and length.

“Fiber mascaras offer less smudging and contain ingredients that condition the lashes,” she explains. They contain “fibers that adhere to your natural lashes to make them look noticeably denser and more voluminous.”

Just be prepared that you may need to work a little harder to remove them come bedtime.

Try Milk Makeup KUSH Mascara or MAC Magic Extension 5mm Fibre Mascara.

There’s no truth to the myth that mascara is made of bat poop. On the other hand, many formulas do contain guanine, which is derived from fish scales.

Today, mascara formulas are closely regulated to ensure safety.

However, you should still take some extra precautions when selecting and wearing a mascara. These include steering clear of ingredients that can cause irritation, and thoroughly and gently removing your mascara after each and every wear.


Victoria Stokes is a writer from the United Kingdom. When she’s not writing about her favorite topics, personal development, and well-being, she usually has her nose stuck in a good book. Victoria lists coffee, cocktails, and the color pink among some of her favorite things. Find her on Instagram.