Eyelash serums: the downside of longer lashes

But luscious lashes aren’t the only thing the serums may deliver. These products can contain ingredients that come with nasty side effects.

What we found

Several eyelash serums we found on shop shelves contain ingredients called prostaglandins. These drugs are used to treat glaucoma, an eye disease that can cause blindness. One side effect of the medication for glaucoma patients is that their eyelashes can get longer and darker.

This discovery led to prostaglandins becoming a popular ingredient in eyelash serums.

Prostaglandins are a prescription medicine but there’s an exception for lash serums (and other products) that contain low levels of the drugs– 10mg per litre or less. This exception means they can be sold without a prescription. Products readily available include Flash Eyelash Serum, Lilash and Revitalash.

These products can contain ingredients that come with nasty side effects.

However, the use of prostaglandins – even at low concentrations – in over-the-counter consumer products has sparked health concerns.

The European Commission recently kicked off an investigation into the safety of prostaglandins in cosmetics after reports of “serious undesirable effects”, including swollen eyelids, burning eyes and hyperpigmentation.

The commission’s review follows a 2018 report by the German Federal Institute for Risk Assessment that couldn’t find evidence of any dose at which eyelash growth can be enhanced without adverse effects occurring.

Other countries, including Australia and Canada, don’t allow eyelash serums containing prostaglandins to be sold without a prescription. Lilash was pulled from shelves in Australia in 2018 after the distributor there was found to be selling it in beauty salons without approval.

Risk of irreversible effects

Wellington ophthalmologist Dr Jesse Gale, a glaucoma specialist, is worried about the potential for these products to cause irreversible side effects.

“Prostaglandins are potent at very low concentrations” Dr Gale said.

“Some [glaucoma] patients get red eyes, some get darker coloured irises, some get long dark eyelashes, some get a sunken appearance from loss of orbital tissue around the eye.”

While most side effects are reversible if you stop using the product, that’s not always the case. Patients taking glaucoma drops to protect their vision are supervised by their doctor, but people using cosmetic products might be unaware of the side effects, Dr Gale said. He believes all products should provide information on these risks.

“The side effects that are most likely to be long lasting or permanent would be atrophy of the orbital tissue causing a sunken eye, or increased pigmentation on the eyelid causing a panda eye or eye shadow appearance.”

US Pacific University College of Optometry Assistant Professor Tracy Doll believes cosmetics containing the drugs should be prescription-only.

A 2020 survey she undertook of 154 consumers who had tried over-the-counter serums found 44 percent had stopped using them. The most common reason was the side effects.

While companies are keen to promote the benefits of eyelash serums, information on the risks is harder to find. There were no warnings on the packs of Flash Eyelash Serum or Lilash. The only information about the potential side effects was in small print on leaflets inside the sealed boxes.

For some consumers, there’s a greater risk. Doll cautioned that cancer patients are more prone to experiencing side effects from prostaglandins.

“PGA [prostaglandin] serums can cause inflammation, which can make dryness from chemotherapy worse,” she said.

One brand, Revitalash, claimed on its website “there was no potential for [the serum] to have a significant effect” on those breastfeeding, pregnant or undergoing chemotherapy. When we contacted the company, it didn’t provide evidence supporting these claims.

Lash complaints

Since 2009, the Ministry of Health has received three complaints about LiLash and one about Revitalash growth serums.

Under the Medicines Act, products containing prostaglandins advertised as having a therapeutic purpose are considered medicines and require approval before they can be sold. Therapeutic claims include those that a product can influence or modify a “physiological process” – such as making your eyelashes grow.

In 2019, Medsafe wrote to the JSL Group, which distributes Lilash and Flash Eyelash Serum, about the therapeutic claims made for its serums.

A Ministry of Health spokesperson said it understood “the company took advice on its advertising approach” as a result of Medsafe’s investigation.

Lilash was previously promoted with the claim the serum provided “stronger, longer lashes in just 6-8 weeks”. After Medsafe’s investigation, this claim was amended to lashes “appear stronger and healthier”. Adding modifiers such as “appear to” is one of the tactics companies use to temper product claims and try to avoid falling foul of the Medicines Act.

JSL Group director James Lee defended the serums the company sells, stating they’re “purely cosmetic” and “not a therapeutic good”.

No further action was taken against the company after Medsafe’s investigation as the matter was considered to be a “lower risk issue”. “The company has been informed of the law and its obligations, and the matter will remain open should further complaints be received,” a ministry spokesperson said.

Any moves to restrict sales of these products are likely to depend on the results of the investigation being done by European regulators. The Ministry of Health said Medsafe “will consider any European recommendation for application in New Zealand”.

Eyelash serums

Flash Eyelash Serum

Price: $64 (2ml)
Prostaglandin listed: Dehydrolatanoprost
Claims include: “Long, Sexy, Curled Lashes. Fast.” Physician formulated.” “Safe for sensitive eyes.” “Guaranteed happiness.”
Fine print warnings: If mild or moderate redness occurs, discontinue use, - at least temporarily - until symptoms resolve. If severe swelling, redness, pain or change in vision occur, discontinue use immediately and consult a physician. Flash Eyelash Serum has not been tested under all possible conditions.

Lilash Eyelash Serum

Price: $125 (2ml)
Prostaglandin listed: Isopropyl phenylhydroxypentene dihydroxycyclopentylheptenate *
Claims include: “Lashes appear stronger and healthier in just 8-12 weeks.” “Award winning lash serum as voted by NZ's top magazines.” “Physician formulated and ophthalmologist tested.”
Fine print warnings: Do not use if you are currently pregnant or nursing, or you’re undergoing chemotherapy. If mild to moderate redness or irritation occurs, discontinue use until symptoms resolve. If severe redness, pain, or swelling or change in vision occur, seek medical attention immediately. A darkening of the skin may occur over time where Lilash is being applied. This usually resolves with discontinued use. Lilash has not been tested under all possible conditions.

*This is the chemical name for Dehydrolatanoprost.

Revitalash Advanced Eyelash Conditioner

Price: $129 (2ml)
Prostaglandin listed: Dechloro Dihydroxy Difluoro Ethylcloprostenolamide
Claims include: “Physician developed, breakthrough eyelash conditioning formula designed to enhance the beauty of less-than-ideal lashes.”
Fine print warnings: Do not get in eye. If irritation develops, reduce frequency of use until irritation resolves. If irritation persists or is excessive, discontinue use and consult a physician. Some users have reported a faint darkening of the eyelash base, if this is of concern, do not use.

On prescription

Latisse is the sole prescription-only eyelash serum available in our market. It contains a prostaglandin called bimatoprost and is used to treat hypotrichosis, a condition where hair doesn’t grow. Side effects of the serum include eye irritation, swelling, change of eye colour, blurred vision and even loss of eyelashes.