Glyoxylic Acid

Glyoxylic Acid and pregnancy

Caution Advised

• Absorbed into the body
• Irritant

Glyoxylic Acid is an alpha-keto acid used as a buffering agent and in some hair straightening treatments. When applied to skin or scalp, the compound can be absorbed systemically and metabolized to oxalate, which is excreted by the kidneys. The concern during pregnancy is related to systemic exposure rather than direct reproductive toxicity. While specific pregnancy safety studies are limited, the systemic absorption of glyoxylic acid and its conversion to oxalate raises theoretical concerns. During pregnancy, kidney function changes and the body's ability to handle oxalate metabolism may be affected. Additionally, the compound's irritating properties could be problematic for skin that may be more sensitive during pregnancy. ECHA's classification of glyoxylic acid as irritating and its potential for systemic effects warrant caution. No regulatory body has explicitly prohibited glyoxylic acid during pregnancy, but the lack of safety data combined with known systemic absorption and irritation potential suggests a conservative approach. Many dermatologists recommend avoiding products with significant glyoxylic acid content during pregnancy, particularly professional hair straightening treatments where exposure is substantial. For minimal concentrations used as buffering agents, the risk is likely lower but still uncertain.

Glyoxylic Acid and breastfeeding

Caution Advised

• Absorbed into the body

Glyoxylic acid can be absorbed systemically and is metabolized to oxalate in the body. While there is no direct evidence of transfer into breast milk, the systemic absorption and metabolism raise theoretical concerns about potential effects on breastfed infants. The irritating properties of glyoxylic acid could also be problematic if applied to areas of skin that may come in contact with a breastfed infant. The lack of specific safety data for breastfeeding combined with known systemic absorption suggests caution is warranted. While minimal amounts used as a buffering agent in rinse-off products likely pose little risk, products containing significant concentrations of glyoxylic acid (such as hair straightening treatments) are best avoided during breastfeeding until more safety data is available. Dermatologists generally recommend postponing professional treatments with glyoxylic acid until after weaning.

Glyoxylic Acid and postpartum

Safe to Use

• Irritant

For postpartum women who are not breastfeeding, the primary concern with glyoxylic acid is its irritating properties rather than systemic effects. Skin may still be recovering from pregnancy and could be more sensitive to irritating ingredients. If using products containing glyoxylic acid, those with sensitive or compromised skin should introduce them gradually and monitor for irritation. Professional treatments should be approached with caution, and patch testing is advisable before full application.

Glyoxylic Acid and trying to conceive

Safe to Use

There is no evidence that topical glyoxylic acid affects fertility or reproductive function. The systemic absorption from cosmetic use is generally low enough that it is unlikely to impact conception or early pregnancy before awareness. While the ingredient can be used when trying to conceive, women who achieve pregnancy should consider discontinuing products with significant glyoxylic acid content as a precautionary measure. For buffering agent concentrations in regular cosmetics, the risk is minimal.

Glyoxylic Acid and PCOS

Safe to Use

Glyoxylic Acid does not have known hormonal activity or effects on androgen metabolism. The ingredient functions as a buffering agent and does not interfere with hormone levels or insulin sensitivity. There is no evidence that glyoxylic acid affects PCOS-related metabolic or hormonal factors. The primary considerations for PCOS patients are the same as for the general population—potential skin irritation and individual tolerance. Women with PCOS can use products containing glyoxylic acid without concerns about hormonal interference. However, those with sensitive or inflammation-prone skin should monitor for irritation, as PCOS-related skin conditions may make individuals more susceptible to irritating ingredients.

Glyoxylic Acid and general use

Safe to Use

• Irritant

Glyoxylic Acid is used in cosmetics primarily as a buffering agent to adjust and maintain pH levels in formulations. In hair straightening products, it serves a more active role but at higher concentrations than typically found in skincare. According to ECHA, glyoxylic acid is classified as causing serious eye damage (Category 1) and skin irritation (Category 2). Users should avoid contact with eyes and may experience skin irritation, particularly at higher concentrations. Professional treatments should be performed with appropriate precautions and ventilation. For the general population, glyoxylic acid in low concentrations as a buffering agent is generally tolerated, though individuals with sensitive skin may experience irritation. Professional hair straightening treatments using glyoxylic acid should be approached with caution, ensuring proper application techniques and post-treatment care to minimize adverse effects.

Everything else flagged for the same profiles

• Flagged in pregnancy
• Flagged in breastfeeding

Related ingredients

Ingredients that raise the same concerns.

• Parfum/FragranceIrritant, Absorbed into the body
• Salicylic AcidIrritant, Absorbed into the body
• Lavandula Angustifolia OilIrritant, Absorbed into the body
• Melaleuca Alternifolia Leaf OilIrritant, Absorbed into the body
• EugenolIrritant, Absorbed into the body
• Rosmarinus Officinalis Leaf OilIrritant, 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.