Azelaic acid is a safe compound with an excellent tolerability profile, as confirmed by animal and clinical studies.

Azelaic acid is

• Well tolerated
• Neither phototoxic nor photosensitizing
• Not mutagenic
• Not teratogenic
• Does not induce bacterial resistance
• Safe for use during pregnancy and lactation
• Does not bleach hair and clothes

The low incidence of side effects observed in the acne and rosacea studies mainly included cutaneous symptoms such as burning and itching which were transient and of mild to moderate intensity. [1]

The highest incidence was observed during the first month of treatment, and gradually decreased throughout the course of therapy.

References

[1] Elewski BE, Fleischer AB Jr, Pariser DM. A comparison of 15% azelaic acid gel and 0.75% metronidazole gel in the topical treatment of papulopustular rosacea: results of a randomized trial. Arch Dermatol 2003 ;139:1444-50.