Panthenol, also known as provitamin B5, is commonly included in topical formulations for treating minor skin irritations, including sunburn. Its use is scientifically supported, though the strength of evidence is moderate (rated 3/5). Panthenol is known for its moisturizing, anti-inflammatory, and wound-healing properties. Several in vitro and in vivo studies have demonstrated that panthenol can enhance skin barrier repair, reduce transepidermal water loss, and promote epithelialization, which are beneficial effects in the context of sunburned skin.

Clinical studies, though limited in number and size, suggest that topical panthenol can reduce erythema, inflammation, and discomfort associated with sunburn. For example, a double-blind randomized controlled trial published in 1995 found that a panthenol-containing ointment reduced subjective symptoms of irritation and improved skin hydration compared to placebo. However, larger and more robust clinical trials specifically targeting sunburn are lacking, and most available evidence is extrapolated from studies on general skin irritation or wound healing.

Overall, while panthenol is widely used in after-sun care products and there is reasonable scientific rationale and some clinical data supporting its efficacy in alleviating sunburn symptoms, the evidence is not definitive. More high-quality clinical trials focused specifically on sunburn are needed to fully validate its use for this purpose.