Can You Use Sulfur Acne Treatment While Pregnant?

Topical sulfur at concentrations below 6% is considered potentially safe during pregnancy, making it one of the acne treatments that does not need to be shelved when you see a positive test. That said, the evidence base is thin. Sulfur has been used in dermatology for centuries, yet formal studies specifically enrolling pregnant participants are scarce, which is why recommendations lean on pharmacokinetic reasoning and long clinical experience rather than large trials. Understanding what makes sulfur relatively low-risk, what forms and concentrations matter, and how it stacks up against other pregnancy-compatible options can help you and your provider make a more informed choice.

Why Sulfur Gets a Cautious Green Light

Sulfur works against acne through two main actions: it helps shed dead skin cells that clog pores, and it has mild antimicrobial properties that reduce the bacteria involved in breakouts. When applied to the skin in a wash, mask, or spot treatment, very little of it makes its way into the bloodstream. Older pharmacokinetic data estimates that roughly 1% of topically applied sulfur is absorbed systemically.¹ That low absorption rate is the central reason sulfur is not flagged as a high-concern ingredient during pregnancy. With so little reaching the circulation, the amount available to cross the placenta is negligible under normal use conditions.

A 2025 narrative review in the dermatology literature states plainly that topical products with sulfur concentrations under 6% are potentially safe for pregnant and lactating individuals, as well as children older than two months.² Most over-the-counter sulfur acne products fall in the 2–5% range, which puts them within that window. Prescription sulfur washes sometimes go as high as 10%, so the concentration on the label matters more than many people realize.

The Gap Between “Potentially Safe” and “Proven Safe”

One thing worth being honest about: the safety language around sulfur in pregnancy is cautious for a reason. A review of topical acne drugs noted that agents like benzoyl peroxide, salicylic acid, sulfur, and sodium sulfacetamide all show some degree of absorption through the skin and remain largely unregulated because serious adverse effects beyond local irritation are rare. But the same review explicitly advised caution during pregnancy, childhood, and lactation because relevant studies are lacking.³ In practical terms, that means no one has run a randomized controlled trial specifically testing sulfur face washes in pregnant participants. The reassurance comes from the fact that sulfur is a naturally occurring element in the body, its systemic absorption from topical use is minimal, and decades of widespread use have not turned up signals of harm.

This gap between “no evidence of harm” and “rigorously tested and confirmed safe” exists for many topical products used in pregnancy. It does not mean sulfur is dangerous. It means that if you are someone who wants the strongest possible evidence before applying anything during pregnancy, sulfur sits in a gray zone that your provider can help you navigate based on the severity of your acne and your personal comfort level.

Sulfacetamide-Sulfur Combination Products

Some prescription acne and rosacea treatments pair sulfur with sodium sulfacetamide, a sulfonamide antibiotic. This combination raises a separate set of questions because sulfacetamide works by interfering with bacterial folic acid production, and folic acid is critically important in early fetal development. Despite this theoretical concern, no reports of birth defects have been linked to sulfacetamide, and the combination treatment is not contraindicated during pregnancy.⁴ Historically, sulfacetamide carried a Category C designation under the old FDA pregnancy labeling system, meaning animal studies showed some risk but human data were insufficient to confirm or rule it out.

If you are already using a sulfacetamide-sulfur product and find out you are pregnant, the existing evidence does not suggest you need to panic. But because the theoretical mechanism of concern involves folic acid, many providers prefer to switch patients to a simpler sulfur-only product or another first-line option during the first trimester when neural tube development is most sensitive. This is a precautionary choice, not a response to documented harm.

Common Side Effects That Pregnancy Can Amplify

Sulfur’s most frequently reported side effects are its characteristic rotten-egg smell and dry, flaky skin. Beyond these, some users experience local irritation or, rarely, contact allergy.² During pregnancy, these side effects can feel worse than they would otherwise. Hormonal shifts often leave skin more sensitive and reactive, and the heightened sense of smell many pregnant people experience in the first trimester can make sulfur’s odor genuinely intolerable.

If dryness becomes a problem, reducing your frequency of use from daily to every other day often helps, as does applying a fragrance-free moisturizer immediately after the sulfur product dries. Leave-on treatments like spot gels tend to be more drying than wash-off formulas like cleansers or masks, so the format you choose affects tolerability. Nausea triggered by the smell is harder to manage. Some brands mask the odor better than others, but if the scent is a dealbreaker, switching to an odorless alternative like azelaic acid is a perfectly reasonable move.

How Sulfur Compares to Other Pregnancy-Compatible Options

Sulfur is far from the only acne-fighting ingredient considered acceptable in pregnancy. A narrative review of acne treatment during pregnancy and lactation identified benzoyl peroxide, azelaic acid, and keratolytic agents as suitable topical therapies for mild to moderate breakouts.⁵ Each has its own profile of strengths and trade-offs.

• Benzoyl peroxide: Kills acne-causing bacteria on contact and is available in concentrations from 2.5% to 10%. It is the most widely used over-the-counter acne ingredient in pregnancy. The main downside is that it can bleach fabric and may cause dryness or peeling, especially at higher strengths.
• Azelaic acid: A naturally occurring acid that tackles both inflammation and abnormal skin-cell turnover. A retrospective comparison of topical treatments used during pregnancy found that azelaic acid at 20% outperformed both erythromycin and clindamycin in terms of improvement and patient satisfaction.⁶ It tends to be well tolerated, though some people notice mild stinging when they first start using it.
• Topical antibiotics: Erythromycin and clindamycin are sometimes prescribed for inflammatory acne during pregnancy. They are generally considered safe but are usually combined with another agent to reduce the chance of bacterial resistance.

Sulfur occupies a somewhat niche position in this lineup. It is milder than benzoyl peroxide and less well-studied than azelaic acid, but it can be a good fit for people who react poorly to both of those options or who prefer a more traditional, minimally processed ingredient. Some people also use sulfur alongside benzoyl peroxide, alternating the two to manage different aspects of their breakouts without overloading the skin with a single ingredient.

What You Should Absolutely Avoid

While sulfur and the options above are generally considered acceptable, several common acne treatments are firmly off-limits during pregnancy. The most important to know about are retinoids and certain oral medications.

Oral isotretinoin is a well-established teratogen, meaning it can cause serious birth defects, and is never used in pregnancy. Oral tetracycline antibiotics, including doxycycline and minocycline, are also contraindicated after the first trimester because they can affect fetal bone and tooth development. Topical retinoids like tretinoin and adapalene are more nuanced. A large Nordic cohort study that followed over 2,000 infants exposed to topical retinoids during pregnancy found no increased risk of major birth defects compared to unexposed infants.⁷ That finding is reassuring for anyone who used a retinoid cream before realizing they were pregnant, but most guidelines still recommend avoiding topical retinoids during pregnancy as a precaution, given the known dangers of oral retinoids and the availability of safer alternatives.

Spironolactone, an oral anti-androgen sometimes prescribed for hormonal acne, is also contraindicated because it can interfere with the development of male reproductive organs. And high-dose salicylic acid, particularly in chemical peels, is generally avoided, though low-concentration salicylic acid in a face wash that is quickly rinsed off is often considered acceptable. If you are unsure about any product in your current routine, bringing the ingredient list to a prenatal visit is the simplest way to sort it out.

The Sulfur and Sulfa Allergy Mix-Up

One surprisingly common concern that can steer pregnant people away from sulfur unnecessarily is a listed allergy to “sulfa” drugs. The confusion between sulfur, sulfa, sulfites, and sulfates is widespread among both patients and health professionals. An Australian Prescriber article put it bluntly: some patients who have had a reaction to sulfonamide antibiotics get labelled “sulfur allergic,” which then leads them to avoid sulfites in food, sulfates in shampoo, and elemental sulfur in skincare, none of which share the same allergy pathway.⁸

The pharmacology behind this distinction matters in a practical way. Sulfonamide antibiotics contain a specific chemical structure called a sulfonylaryamine group. Elemental sulfur, the kind in acne masks and spot treatments, does not share that structure. A review in the Annals of Allergy, Asthma & Immunology emphasized the important distinctions between antimicrobial sulfonamides, non-antimicrobial sulfonamides, and sulfones, noting that the reaction mechanisms are different and that people allergic to one group do not necessarily react to another.⁹ Research has further shown that people with documented sulfonamide antibiotic allergy tend to have higher allergy rates across the board, not specifically to other sulfur-containing substances, suggesting a generally reactive immune system rather than a targeted sulfur sensitivity.¹⁰

If your medical chart says “sulfa allergy,” that almost certainly refers to an antibiotic like sulfamethoxazole-trimethoprim, and it is not a reason to avoid a sulfur face wash. That said, mention it to your provider so they can confirm what the documented reaction actually was, especially if you are considering a prescription sulfacetamide-sulfur product, which does contain a sulfonamide component and falls into a different category than plain elemental sulfur.

Practical Tips for Using Sulfur Products During Pregnancy

If you and your provider decide sulfur is a reasonable choice, a few practical steps can make the experience smoother. Start with a wash-off product like a sulfur cleanser or a short-contact mask rather than a leave-on treatment. Wash-off formulas limit the skin’s exposure time, reduce dryness, and keep the smell brief. Most sulfur cleansers are designed to sit on the skin for 30 seconds to a minute before rinsing, which is enough contact time for the active ingredient to work on surface bacteria and excess oil.

Look for concentrations in the 2–5% range. Products in this zone deliver meaningful acne-fighting activity without the irritation potential of higher-strength formulations. If your skin tolerates a lower concentration well but your acne persists, you can try increasing frequency before jumping to a higher concentration. And if you are combining sulfur with other actives like benzoyl peroxide, stagger them, using one in the morning and the other at night, rather than layering them in the same routine. Pregnancy skin can be less forgiving about product overload than your skin was before.

Fragrance-free formulations are easier to tolerate when nausea and scent sensitivity are part of your daily life. Some sulfur products add fragrance to mask the natural smell, but those fragrances can trigger headaches or nausea independently. A product that smells mildly unpleasant for 60 seconds during a face wash may be more tolerable than one that leaves a perfumed layer of fragrance on your skin for hours.

Why Pregnancy Acne Is So Common in the First Place

Breakouts during pregnancy catch many people off guard, especially those who had clear skin before conceiving. The culprit is a surge in androgens, the same hormones that drive acne during puberty. Androgen levels rise during pregnancy to support placental function and fetal development, and a side effect is increased oil production in the skin. The extra sebum, combined with hormonal changes in how skin cells turn over, creates the conditions for clogged pores and inflammatory breakouts.

Acne tends to be most pronounced in the first and second trimesters, when hormonal fluctuations are steepest, though some people experience it throughout pregnancy or only in the third trimester. The unpredictability makes it hard to decide how aggressively to treat breakouts. A mild first-trimester breakout might resolve on its own as hormones stabilize, while a persistent second-trimester flare could justify starting a topical treatment. For many people, combining a gentle sulfur or benzoyl peroxide product with good basic skincare, meaning regular cleansing, non-comedogenic moisturizer, and sun protection, manages the problem well enough without escalating to prescription treatments.

One thing that does not help is the guilt some people feel about treating acne during pregnancy. The cultural pressure to avoid everything during pregnancy can lead to unnecessary suffering. Untreated acne can cause scarring, pain, and real psychological distress, and treating it with well-established, low-risk topical ingredients is not the same as taking unnecessary risks. A short conversation with a dermatologist or midwife can often put the risk into perspective and free you to address the breakouts rather than just endure them.