There is very little human research on this front. A few randomized controlled trials in Iran have investigated lemon balm for psoriasis, itching after a burn, and oral lichenoid lesions.
Postburn itching: A 2019 study in hospitalized burn patients in Iran found that the participants who drank lemon balm tea twice daily, with snacks, reported less itching in the third week after the burn than the participants who didn’t drink lemon balm tea.[1] However, this study had methodological and reporting issues, with a risk of bias in multiple areas.[2]
Psoriasis: A study conducted in Iran in 2021 found that taking a syrup of lemon balm, Rosa damascena, and dates three times a day decreased disease severity and itching in people with psoriasis.[3] Research in mice reported that a lemon balm decoction might help psoriasis by reducing dryness and improving the skin’s barrier function.[4] More research in humans is needed.
Lichenoid lesions: A 2022 trial in Iran compared a lemon balm cream to triamcinolone paste (a topical steroid) for the treatment of erosive oral lichenoid lesions (inflamed patches in the mouth with a characteristic appearance), including oral lichen planus, drug-induced lichenoid reactions, and contact or transplant lichenoid reactions. The participants who used the lemon balm gel reported a greater reduction in pain compared to triamcinolone but had less of a reduction in lesion size.[5]