Squalene is a natural lipid found in human sebum and certain plant oils, noted for its emollient and antioxidant properties. Its use in supporting or treating dermatitis—particularly atopic and seborrheic dermatitis—is based on its role in maintaining skin barrier function and hydration. Scientific evidence suggests that squalene helps restore the lipid layer of the skin, which is often compromised in dermatitis, leading to dryness, irritation, and increased transepidermal water loss. Studies have demonstrated that topically applied squalene (or its more stable derivative, squalane) can improve skin hydration, enhance barrier repair, and exhibit anti-inflammatory effects, making it a potentially beneficial adjunct in dermatitis management.

However, while some small studies and in vitro analyses support these mechanisms, there is a lack of large, high-quality clinical trials specifically evaluating squalene as a treatment for dermatitis. Most evidence comes from studies on general skin barrier function and moisturizing effects, rather than direct trials in dermatitis patients. Therefore, while the scientific rationale is sound and some supportive data exist, the overall evidence is limited and does not yet meet the highest standards of clinical validation for dermatitis treatment. Squalene is generally considered safe and is widely used in cosmetic and skincare formulations for sensitive and dry skin, including those with dermatitis.