When a pregnant client asks whether she can keep using her lash serum, the answer depends on one thing: whether the formula contains a prostaglandin analogue. If it does, advise her to stop and take it up with her doctor. The drug label for bimatoprost, the best-known analogue, says there are no adequate studies in pregnant women, and cosmetic lash growth is elective, so there is little reason to take the risk. If the serum is a conditioning formula built on peptides, hyaluronic acid or hydrolysed proteins, the picture is calmer, but “calmer” is not the same as “studied in pregnancy”, and you should say so.
| Serum type | What to check | What to tell the client |
|---|---|---|
| Growth serum with a prostaglandin analogue (bimatoprost, isopropyl cloprostenate, ethyl tafluprostamide and similar) | INCI list | Pause it and ask her doctor; discuss breastfeeding with the doctor too |
| Serum marketed as “hormone-free” | INCI list, not the front label | The claim alone proves nothing; verify the ingredients |
| Conditioning serum (hydrolysed keratin, collagen, hyaluronate, peptides) | Preservative, any new irritation | Reasonable to continue if she tolerates it, with a doctor’s approval |
Why prostaglandin analogues are the concern
Bimatoprost was developed as a glaucoma drug, and its eyelash version (Latisse) is a prescription product. Its current US label states that there are no adequate and well-controlled studies in pregnant women, and that postmarketing experience shows no increase in major birth defects or miscarriages. The same label reports abortion and early delivery in animal studies at high oral doses, with a no-effect level of only 2.6 times the human systemic exposure from ophthalmic use. That narrow margin is why many physicians choose to avoid cosmetic bimatoprost altogether in pregnancy.
You may still see “Pregnancy Category C” quoted. That letter system was part of older labels; the FDA’s Pregnancy and Lactation Labeling Rule, effective June 2015, replaced the letters with a written risk summary. Quote the current wording, not the category.
Absorption is also not zero. In a 15-person study on healthy adults with eye-drop dosing, blood levels peaked within 10 minutes and were below the detection limit (0.025 ng/mL) in most subjects within 1.5 hours. That study used drops in the eye rather than application along the lash line, so treat it as evidence that the molecule does reach the bloodstream, not as a precise figure for serum users. Figures such as “1-5% absorption” circulate online, but we could not trace them to the label, so we do not use them.
The bigger problem sits in the cosmetic market. Over-the-counter serums often contain analogues that were never approved as drugs. The UK government’s review of the category names isopropyl cloprostenate (a travoprost derivative), bimatoprost and ethyl tafluprostamide among the four most common. In February 2026 the EU’s Scientific Committee on Consumer Safety concluded that three such analogues, including isopropyl cloprostenate, cannot be considered safe in products intended to promote lash and brow growth, citing their potent pharmacological activity. In July 2026 the European Commission notified a draft regulation that would add prostaglandins and their analogues to the list of banned cosmetic substances. At the time of writing we found no confirmation that it has been adopted, so check the current status before you update your client documents.
Reading the label before you answer
“Hormone-free” is not a defined term on lash serum packaging, so it cannot tell you whether an analogue is present. Go to the INCI list and look for isopropyl cloprostenate, ethyl tafluprostamide (listed as dechloro dihydroxy difluoro ethylcloprostenolamide), methylamido dihydro noralfaprostal, bimatoprost or norbimatoprost. If a client brings in a product with no ingredient list, treat it as unverified and ask her to stop until she can produce one. The same rule applies to products her friends have sent her from abroad.
What pregnancy does to the lash cycle
Clients often arrive worried about thin or “lazy” lashes. Two things are worth knowing. During pregnancy, more scalp follicles than usual stay in the growth (anagen) phase, which is why hair often feels fuller. After delivery they drop into the resting (telogen) phase together, and the result is postpartum telogen effluvium. It typically starts 2-4 months after delivery; in one study the average onset was 2.9 months, the peak 5.1 months and the end 8.1 months.
That timeline comes from scalp hair studies. A consultant dermatologist quoted by Good Housekeeping UK says that in some women the shedding also affects lashes and brows, but we found no authoritative data on how often, or on a lash-specific timeline. Use it as a reasonable expectation, not a promise. Our guide to the stages of hair growth and the article on hormones and lash growth cover the biology if you want to brief your team.
A practical example: a client delivers in March and books in for a lash lift in July, saying her lashes are falling out and asking for a growth serum. Four months postpartum is squarely inside the expected shedding window, so the useful conversation is about timing and expectations, and whether she is breastfeeding and has cleared any serum with her doctor. A growth stimulant is not the first answer.
Pregnancy also changes the skin around the eye. Between 5% and 70% of pregnant women develop chloasma, a reversible darkening that can involve the eyelids, and hormonal shifts are linked to dry eye in pregnancy. If a client reports darker lids or gritty, irritated eyes, do not assume your product or her serum is to blame, and refer her on if it persists.
Conditioning serums: what you can and cannot say
The reasoning behind conditioning formulas is sound: they coat and soften the existing hair shaft rather than acting on the follicle. For example, Nutrilash lists water, hydroxyethylcellulose, VP/VA copolymer, soluble collagen, hydrolysed keratin, sodium hyaluronate and phenoxyethanol, with no prostaglandin analogue on the published ingredient list. Phenoxyethanol is the preservative, and the EU caps it at 1.0% in finished cosmetics.
What you cannot say is that any particular serum has been tested in pregnant women. For most peptide ingredients we found only limited pregnancy-specific data, so the honest line is “no known concern, no dedicated studies, check with your doctor”. Pair that with a simple rule for the chair: if a client starts a new product and her eyelids redden or itch within the first week, she stops it and you document it.
Adjusting services for pregnant clients
If she pauses her serum but still wants a service, apply the same caution to the treatment. Our standing guidance is to avoid lash lifts in the first trimester, and the detailed protocols are in our article on lash lifts during pregnancy, with more in pregnancy lash treatments and the contraindications for lash lift. Brow services follow the same logic; see brow lamination during pregnancy.
If she proceeds in a later trimester after her doctor’s go-ahead, three habits matter most. Run a new patch test 24 to 48 hours beforehand, even for a regular client, because skin reactivity changes. Ventilate the room well. And keep lotion at least 1 mm from the lash root so the product does not touch the skin.
Positioning needs more thought than most technicians give it. Supine hypotensive syndrome, where the uterus compresses the large vessels and drops blood pressure, typically becomes a concern after 20 weeks; the RCOG already advises against exercises lying flat on the back from 16 weeks. Obstetric guidance for a patient lying on her back after 20 weeks is a left lateral tilt of 15 to 30 degrees, usually a wedge under the right hip. We found no source that shows a specific semi-recline angle prevents compression, so do not rely on a 30-45 degree backrest alone. Use the wedge, keep sessions short, and ask her to tell you at once if she feels dizzy, nauseous, clammy or faint. Those symptoms mean sitting her up or turning her onto her left side.
Aftercare and documentation
Keep aftercare simple: a mild, fragrance-free cleanser and makeup remover that will not strip an already sensitive lid. Our Lash & Brow Cleansing Foam and Gentle Makeup Remover are formulated for sensitive skin and are designed for use before and after lash lifts.
Your role is to manage risk, not to give medical advice. Record in the client file that she has been advised to consult her doctor, which serum she uses, the ingredient list you checked, the gestational week, and the date of the patch test, together with her signed consent. If you are building your own range, a private label lash serum lets you control the ingredient list and ask your manufacturer for documentation on what is and is not in the formula. You can also browse our serum category for ready-made conditioning options.
The takeaway for the consultation is simple: read the INCI list, pause any prostaglandin analogue, set realistic expectations for the postpartum shedding window, and adjust positioning after 20 weeks. Before your next pregnant client books in, update your consultation form with those four checks and review the pregnancy protocols linked above with your team.
