Calendula (Calendula officinalis), also known as pot marigold, has a long history of use in herbal medicine for its anti-inflammatory, antimicrobial, and wound-healing properties. Its use for diaper rash is supported by both traditional applications and a modest body of scientific evidence. Calendula extracts contain triterpenoids, flavonoids, and other phytochemicals believed to contribute to skin healing and reduction of inflammation.

Several clinical studies have investigated the efficacy of calendula for diaper dermatitis. A randomized controlled trial published in Pediatric Dermatology (2012) compared calendula ointment to aloe vera cream in infants with diaper rash, finding both treatments effective, with no significant difference between them. Another study in Iranian Journal of Nursing and Midwifery Research (2013) found calendula ointment was more effective than commonly used barrier creams in reducing the severity of diaper rash.

Although the number of high-quality, large-scale studies is limited, current evidence suggests that calendula can be beneficial for mild to moderate diaper rash, likely due to its anti-inflammatory and skin-soothing effects. It is generally considered safe for topical use in infants, though rare allergic reactions can occur. Thus, the use of calendula for diaper rash is justified by preliminary scientific validation, and its popularity in over-the-counter creams is based on both tradition and emerging clinical data.