What Is MIT and Why Is It Used in Haircare?

Both methylisothiazolinone and methylchloroisothiazolinone, or MIT and CMIT, are common ingredients used as preservatives in liquid-based beauty products. This is because of their antibacterial properties.¹ Cosmetic products, in particular, can be fertile grounds for bacteria growth due to the presence of water, and combinations of natural and synthetic ingredients, in their formulations. Methylisothiazolinone in hair products, as well as methylisothiazolinone in skincare, can help extend shelf life.²

What methylisothiazolinone is used for can include shampoo, body wash, hair dye, and hairspray, as well as other common beauty products. It also has applications outside of cosmetics, such as methylisothiazolinone in laundry detergent.¹ So, it’s no exaggeration to say that methylisothiazolinone uses are plentiful. But when it comes to MIT as a preservative in hair products, is methylisothiazolinone harmful? The answer is that it really depends on your specific hair and skin type, especially if it’s sensitive, dry, or dandruff-prone. That’s because certain people may have a methylisothiazolinone allergy (or methylchloroisothiazolinone allergy, for that matter), which can result in various types of skin irritation and swelling known as dermatitis.^3,4 Which brings us to our next point.

Why Doesn’t CeraVe Use MIT in Its Haircare Products?

At CeraVe, we’re committed to developing gentle, science-backed products with board-certified dermatologists. We work hard to make sure that all of our offerings have been allergy-tested to ensure they’re safe for all hair and skin types and are free of potentially irritating ingredients like MIT, CMIT, phthalates, sulfates, dyes, parabens, and fragrances.

What This Means for Your Scalp and Hair

While we’re not saying that methylisothiazolinone or methylchloroisothiazolinone are bad for hair or your scalp, CeraVe’s haircare products are specially-formulated without these ingredients. Our formulas are suitable for all hair and skin types—even sensitive or dandruff-prone ones—to leave your hair and the skin underneath it feeling soft, supple, and healthy. You might just find your new favorite system or 2-in-1 below.

Treat yourself to a gentle yet thorough cleanse with CeraVe Gentle Hydrating Shampoo, which helps lock in moisture for healthier-looking locks. This formula contains three essential ceramides, niacinamide, and hyaluronic acid while being free of MIT, CMIT, phthalate, sulfate, parabens, and fragrance. Combine it with CeraVe Gentle Hydrating Conditioner for fresher, softer hair of any type, including all curl patterns and color-treated manes.

If you struggle with dandruff—like almost half of us do, at some point in our lives⁵—check out the flake-fighting CeraVe Anti-Dandruff Hydrating Shampoo and Conditioner. Dermatologists also helped us create this powerful system that can get rid of up to 100% of visible flakes* while still providing gentle nourishment to your hair and scalp. Formulated with 1% pyrithione zinc, along with three essential ceramides, niacinamide, and hyaluronic acid, this system will reduce uncomfortable itchiness and irritation while providing all hair types with tresses that appear visibly healthier and feel softer.

*With regular use as a system.

When you need a quick and effective cleanse that will help eliminate nearly 100% of visible flakes and leave you more comfortable in the process, reach for the CeraVe 2-in-1 Anti-Dandruff Hydrating Shampoo and Conditioner. This formula also stars 1% pyrithione zinc, three essential ceramides, niacinamide, and hyaluronic acid to help relieve an itchy and irritated scalp while nixing the appearance of flakiness.* You’ll be lathered up and ready to go in less time. Plus, your scalp and hair will be left feeling refreshed and healthier.

*With regular use.

For help choosing the right products for your specific skin type and skin concerns, use our Find My Skincare Solution tool.