Ammonium Thioglycolate

Ammonium Thioglycolate and pregnancy

Not Recommended

• Absorbed into the body
• Irritant

Ammonium thioglycolate is a chemical compound used primarily in hair removal creams (depilatories) and permanent wave solutions. It works by breaking down the protein bonds in hair, allowing hair to be dissolved or chemically restructured. While there are no definitive studies proving harm during pregnancy, several factors raise concerns. The ingredient can be absorbed through skin, particularly if skin is broken or irritated, which is more likely during application. Pregnancy makes skin more sensitive and reactive to chemicals. The strong chemical odor can trigger nausea, which is problematic during pregnancy-related morning sickness. Additionally, the chemical's ability to break down protein structures raises theoretical questions about systemic effects, though specific pregnancy studies are lacking. Most obstetricians and dermatologists recommend avoiding chemical depilatories during pregnancy, particularly in the first trimester when fetal organ development is occurring. ACOG doesn't provide specific guidance on this ingredient, but the general medical consensus favors more gentle hair removal methods (like shaving or waxing) during pregnancy. If hair removal is desired, safer alternatives are widely available.

Ammonium Thioglycolate and breastfeeding

Caution Advised

• Irritant
• Absorbed into the body

Ammonium thioglycolate in hair removal products works by chemically breaking down hair proteins. When applied to skin, some absorption can occur, particularly if the skin barrier is compromised. There is no specific data on whether this chemical passes into breast milk. However, the strong odor and potential for skin absorption raise minor concerns. The primary issue is less about milk transfer and more about the chemical exposure and skin irritation during the physically demanding period of caring for an infant. The ingredient's irritant properties could cause significant discomfort. Most dermatologists consider occasional use of depilatories acceptable during breastfeeding if applied to areas away from the breast and chest. However, they recommend patch testing and limiting exposure time. Many breastfeeding mothers prefer gentler hair removal methods that don't involve harsh chemicals. If used, ensure products don't contact breast tissue or areas where infant skin contact occurs.

Ammonium Thioglycolate and postpartum

Caution Advised

• Irritant
• Common allergen

For postpartum women not breastfeeding, the primary concerns with ammonium thioglycolate are skin irritation and allergic reactions rather than systemic effects. Postpartum hormonal changes can make skin more sensitive and reactive to harsh chemicals. If using hair removal products containing this ingredient, follow all label directions carefully, perform patch tests, and limit contact time. Be particularly cautious if you have any postpartum skin changes or increased sensitivity. Alternative hair removal methods may be gentler on hormonally-affected skin.

Ammonium Thioglycolate and trying to conceive

Caution Advised

• Absorbed into the body

When trying to conceive, it's advisable to minimize exposure to chemicals with limited safety data. While there's no direct evidence that ammonium thioglycolate affects fertility, the precautionary approach is to reduce use of harsh chemical products during the TTC phase. The concern is less about proven harm and more about establishing safe habits before pregnancy, since you may not know immediately when conception occurs. Most fertility specialists recommend switching to gentler hair removal methods during the TTC period.

Ammonium Thioglycolate and PCOS

Safe to Use

• Irritant
• Common allergen

Ammonium thioglycolate does not affect hormone levels or interact with androgen activity, making it hormonally neutral for PCOS. It works purely through chemical protein breakdown without systemic hormonal effects. For individuals with PCOS who experience hirsutism (excess hair growth), chemical depilatories can be one option for hair removal. However, PCOS can sometimes be associated with more sensitive or acne-prone skin, which may react more strongly to this irritating ingredient. If considering depilatories for PCOS-related hair growth, always patch test first and follow product directions strictly. Be aware that PCOS skin may be more reactive. Other hair removal methods (laser, electrolysis) may be more effective for managing persistent hirsutism.

Ammonium Thioglycolate and general use

Caution Advised

• Irritant
• Common allergen

Ammonium thioglycolate is used in chemical depilatories and permanent wave solutions because it can break down the disulfide bonds in keratin proteins. This allows hair to be dissolved (in depilatories) or reshaped (in perming solutions). The ingredient is a strong irritant that can cause chemical burns, redness, itching, and allergic reactions if used improperly. It has a strong, unpleasant sulfur smell. The SCCS has documented cases of severe skin reactions, including burns and allergic contact dermatitis. Proper use requires strict adherence to timing instructions and patch testing before each use. It should never be applied to broken, irritated, or recently shaved skin. The EU regulates this ingredient strictly, limiting concentrations and requiring pH controls and warning labels. Products must carry instructions for patch testing and timing. While generally safe when used as directed, the potential for severe irritation means users must follow instructions precisely. It's not suitable for sensitive skin or frequent use.

Everything else flagged for the same profiles

• Flagged in pregnancy
• Flagged in breastfeeding
• Flagged in postpartum
• Flagged in trying to conceive

Related ingredients

Ingredients that raise the same concerns.

• Parfum/FragranceIrritant, Common allergen, Absorbed into the body
• Lavandula Angustifolia OilIrritant, Common allergen, Absorbed into the body
• Melaleuca Alternifolia Leaf OilIrritant, Common allergen, Absorbed into the body
• EugenolIrritant, Common allergen, Absorbed into the body
• Rosmarinus Officinalis Leaf OilIrritant, Common allergen, Absorbed into the body
• DMDM HydantoinIrritant, Common allergen, Absorbed into the body

Where this came from

Truva summarises published guidance from bodies including ACOG, the FDA, the EU SCCS and the Cosmetic Ingredient Review. It has no access to your medical history and it is not a substitute for your doctor, dermatologist or midwife. These assessments have not been reviewed by a clinician, and nothing here is a diagnosis or a prescription. If you are pregnant, breastfeeding or being treated for PCOS, take the ingredient list to the person looking after you.

Assessment last pulled from the ingredient database on 15 September 2026.