If you’re using rosemary oil, be sure to mix it with a carrier oil like olive oil or castor oil. [3] X Trustworthy Source Cleveland Clinic Educational website from one of the world’s leading hospitals Go to source Rosemary oil is intense on its own, and using it directly on your scalp can cause allergic reactions or irritation. Mix 2 to 3 drops of rosemary oil with 1 US tbsp (15 mL) of your carrier oil.

Keep in mind that dry scalp and dandruff are different things. Dandruff is caused by too much oil or a fungal infection on your scalp. If you have dandruff, you can treat it with a dandruff shampoo. If it’s just a dry scalp, use anti-itch shampoo. Dandruff flakes are large and have an oily appearance. Dry skin flakes are small and look dried out.

Clarifying shampoos can be drying, so follow up with a moisturizing conditioner to protect your hair.

Feel free to mix oils as well. Each oil offers its own benefits, and you can get all of those by adding oils together. To work the oil into your hair strands even more, sit under a heated dryer.

Look for hair serums with argan oil, jojoba oil, or sunflower oil for the most hydration.

Even products like gel or hairspray may have drying ingredients that can damage your hair.

If you use relaxers, moisturizing your hair is extra important. Use a hydrating shampoo and a deep conditioner to repair and replenish your hair.

Getting electrolytes is also super important for hydration. Try to eat around 2,300 mg of sodium every day to stay hydrated. [7] X Trustworthy Source Centers for Disease Control and Prevention Main public health institute for the US, run by the Dept. of Health and Human Services Go to source

Your dermatologist will try to determine the cause of your dry scalp and then treat it. They may prescribe a topical ointment or a prescription shampoo to use.