Bar soap for hair, a solid cleanser made from saponified fats and oils, has gained popularity as an alternative to liquid shampoos. An example is Aleppo soap, a traditional Syrian soap made from olive oil and bay laurel oil.
Bar soap for hair offers several benefits. It can clarify hair, remove product buildup, and soothe scalp irritation. Historically, bar soap was the primary method of hair cleansing before the invention of liquid shampoos in the 19th century.