Sunscreen is the most useful thing you can do for your skin during pregnancy. It is also the step most likely to be skipped, because the worry about what's inside them feels overwhelming. This guide covers what the evidence says, how Australian sunscreens are regulated and how to read a label, so you can protect the skin changes that matter most, including hyperpigmentation and melasma.
Why sunscreen matters more during pregnancy
Sun protection is the single most effective step against pregnancy pigmentation, and the evidence for this is unusually strong.
Melasma affects between 50% and 70% of pregnant women.¹ A 12-month trial followed 200 pregnant women using a broad-spectrum SPF 50+ sunscreen with high UVA protection. Among the 185 who completed the study, only 5 developed melasma, an occurrence of 2.7%, compared with 53% observed under usual conditions.¹
That is a large difference for a single intervention. It also explains why pigmentation is so difficult to treat during pregnancy and so much easier to prevent. The hormonal changes of pregnancy make pigment-producing cells more reactive to UV light, so the same amount of sun exposure produces more pigment than it did before. Sunscreen helps remove the trigger that these hormones are responding to.
How sunscreen is regulated in Australia
Australia regulates sunscreen more tightly than most countries, which works in our favour.
Primary sunscreens are regulated by the Therapeutic Goods Administration as therapeutic goods rather than cosmetics.² You can see this on the label as an AUST L number. Listed sunscreens may only contain ingredients from a pre-approved list, and each active filter is permitted at specified concentrations.²
This matters when you are reading advice written overseas. American articles often describe filter approvals and warnings that do not map onto what is on an Australian shelf, and European formulas may contain filters not permitted here. If a product carries an AUST L number, its filters have been assessed against Australian requirements and its SPF claim must be supported by testing to the Australian standard.
Mineral or chemical filters during pregnancy
Do chemical sunscreen filters absorb into the body?
Yes. Several commonly used UV filters are absorbed into the bloodstream at measurable levels.
In a randomised trial, 48 participants applied 1 of 4 sunscreen formulations to about 75% of the body over several days, with 34 blood samples collected across 21 days. All 6 filters tested, including oxybenzone, octinoxate, homosalate, octocrylene, avobenzone and octisalate, reached plasma concentrations exceeding the threshold at which the US regulator requires additional safety testing, and did so on the first day of use.³
These findings do not mean anyone should stop using sunscreen, but what they do establish is that these filters are systemically absorbed, which is the reason the safety questions remain open rather than closed.
Do UV filters reach the baby?
Oxybenzone crosses the placenta. A study of paired maternal and fetal samples detected benzophenone-3, the technical name for oxybenzone, in more than 80% of maternal blood, cord blood, maternal urine and amniotic fluid samples.⁴
The cord blood to maternal blood ratio was above 1.0, meaning concentrations in the fetal samples were higher than in the mother's.⁴ Transfer appears to occur by passive diffusion across the placenta.⁴
What this means for a baby's development has not been established in humans. Separately, several UV filters have shown hormone-related and developmental effects in experimental animal studies, and very few human studies have examined these effects despite widespread exposure.⁵ This presents a reasonable basis to consider which sunscreen to use.
Are mineral sunscreens the better choice in pregnancy?
Mineral filters are a sensible precautionary choice during pregnancy, though not a requirement.
Zinc oxide and titanium dioxide work differently from the filters above. They remain in the outermost layer of skin rather than being absorbed into the body, which sidesteps the absorption question entirely.
The concern sometimes raised about mineral filters, that finely milled particles might penetrate the skin, has been examined directly. In a study applying zinc oxide nanoparticles to volunteers repeatedly over 5 days, the particles did not penetrate into the living layers of the epidermis and produced no cellular toxicity.⁶ You do not need to seek out non-nano formulas, and finely milled zinc is what allows a mineral sunscreen to wear well without a heavy white cast.
One clarification on terminology. Mineral filters are chemicals too. The meaningful distinction is not natural versus synthetic, it is whether a filter stays on the skin or enters the bloodstream.
How to read a sunscreen label
Turn the bottle over and read the active ingredients, not the front-of-pack claims.
You are looking for zinc oxide, titanium dioxide, or both, listed as the active ingredient. If you want to avoid the filters with the most open safety questions, check specifically for oxybenzone (also listed as benzophenone-3), octinoxate (also listed as ethylhexyl methoxycinnamate) and homosalate.
On claims:
- "Oxybenzone free" tells you nothing about the other filters in the bottle, and many products that remove oxybenzone simply substitute another absorbing filter.
- Terms like "reef-safe" have no regulatory definition in Australia.
Look for SPF 50 or 50+ with broad spectrum protection, since UVA is the part of the spectrum most involved in pigmentation. And check the label each time you repurchase, because formulations change.
Fitting sunscreen into a pregnancy routine
Apply sunscreen every morning as the final step, after your serum and moisturiser during pregnancy, and reapply every two hours when you are outdoors.
Most people apply far less than the amount used in testing. For the face and neck, roughly half a teaspoon gets you closer to the protection on the label.
Sunscreen works best alongside the ingredients that address existing pigment. If melasma has already appeared, pairing daily SPF with a serum for pigmentation during pregnancy treats both sides of the problem, since without sun protection any brightening ingredient is working against a trigger that keeps resetting it.
Remember that some sun protection is always better than none. If you have run out of the sunscreen you prefer, use what you have rather than going without. The aim is to change what you buy next time, not to worry about the bottle already in your bag. You can review the wider list in our guide to skincare ingredients to avoid during pregnancy.
References
- Lakhdar H, Zouhair K, Khadir K, et al. Evaluation of the effectiveness of a broad-spectrum sunscreen in the prevention of chloasma in pregnant women. J Eur Acad Dermatol Venereol. 2007;21(6):738–42. doi:10.1111/j.1468-3083.2007.02185.x.
- Therapeutic Goods Administration. Australian regulatory guidelines for sunscreens (ARGS), version 3.0. Canberra: Australian Government Department of Health and Aged Care; 2023.
- Matta MK, Florian J, Zusterzeel R, et al. Effect of sunscreen application on plasma concentration of sunscreen active ingredients: a randomized clinical trial. JAMA. 2020;323(3):256–67. doi:10.1001/jama.2019.20747.
- Song S, He Y, Huang Y, et al. Occurrence and transfer of benzophenone-type ultraviolet filters from the pregnant women to fetuses. Sci Total Environ. 2020;726:138503. doi:10.1016/j.scitotenv.2020.138503.
- Krause M, Klit A, Blomberg Jensen M, et al. Sunscreens: are they beneficial for health? An overview of endocrine disrupting properties of UV-filters. Int J Androl. 2012;35(3):424–36. doi:10.1111/j.1365-2605.2012.01280.x.
- Mohammed YH, Holmes A, Haridass IN, et al. Support for the safe use of zinc oxide nanoparticle sunscreens: lack of skin penetration or cellular toxicity after repeated application in volunteers. J Invest Dermatol. 2019;139(2):308–15. doi:10.1016/j.jid.2018.08.024.
This article is for general information and is not a substitute for personal medical advice. If you have concerns about your skin during pregnancy, speak with your GP, midwife or dermatologist.
