Callus, that is, callus, salicylic acid ointment to callus may take about one to two months, but the specific time is not completely certain, long time persistent use has a certain effect. Callus is a hard and smooth keratinous thickening that occurs when the skin is subjected to long-term pressure and friction. Salicylic acid ointment is a keratin softener, its main ingredient salicylic acid can dissolve keratin, can be used to remove keratin thickening caused by callus. However, the time it takes to remove calluses varies from person to person and usually takes about one month to two months. Salicylic acid ointment should be used under the guidance of a medical professional, and may cause irritation or contact dermatitis during use. If redness, swelling, burning sensation occurs at the site of application, stop the medication immediately and wash off the medication, consult your doctor if necessary. And salicylic acid ointment should be avoided on a large area to avoid causing systemic toxicity. Salicylic acid ointment should not be used on skin ulcers, and it is forbidden for those who are allergic to salicylic acid.