What You Need to Know About The DMDM Hydantoin Side Effects

Most of us would probably choose hair care products based on the benefits they give us. We all want silky, smooth hair. It also doesn’t hurt that the product comes with a pleasing scent. But what about its ingredients? Did you know that are ingredients that can cause hair loss? Unfortunately, some people actually learned firsthand about the DMDM hydantoin side effects.

What is DMDM Hydantoin?

A post shared by Dr.Su (@drsu.official)

White and crystalline in appearance, DMDM hydantoin is an antimicrobial agent which is used mainly for preserving cosmetics and skincare products.

It is common to find DMDM hydantoin in products like shampoos, foundation, makeup bases, moisturizers, hair conditioners, and other related products. Being an antimicrobial agent, DMDM hydantoin prevents the growth of yeast, bacteria, and fungi in these products, thereby making them last longer.

However, these preservatives can also endanger anyone using such cosmetic or skincare products. Among the DMDM hydantoin side effects are that they could cause infection and make the customers sick.

DMDM Hydantoin Side Effects

DMDM hydantoin appears to be an essential ingredient in beauty products, right? Well, not really.

Apparently, it’s a formaldehyde donor. While preserving cosmetic products, DMDM hydantoin releases formaldehyde in small quantities at specific intervals throughout the product’s life span. Exposure to formaldehyde, even in a tiny amount, over time is dangerous (just like sodium lauryl sulfate).

Formaldehyde is hazardous to the human body as it could cause cancer and, more mildly, skin irritation.

Exposure to formaldehyde happens mainly through inhalation and contact with the skin. When products that contain formaldehyde are applied to the hair or skin, there are chances that it could also get into your eyes and nose. And you’ll then begin to experience DMDM hydantoin side effects.

The Class-Action Lawsuit concerning DMDM Hydantoin

It’s widely believed that DMDM hydantoin causes the loss of hair. In fact, there was a recent lawsuit against Tresemmé, a brand that includes DMDM hydantoin among their product (Keratin Smooth Color Shampoo) ingredients.

Over a hundred customers had complained of losing hair in the shower after using their product. Another brand, DevaCurl, faced a similar fate. In the words of their customers, the product damaged their scalps and made their hair fall out in clumps. There were about ten lawsuits against this brand.

The Debate on Safety and DMDM Hydantoin Side Effects

Some experts claimed that the amount of formaldehyde in these products is not enough to cause dermatitis, except in rare conditions. Meanwhile, other experts suggested that even the slightest exposure to formaldehyde can stir up a series of reactions, especially with sensitive people.

8 Surprising Truths About Hyaluronic Acid For Skin

Nonetheless, a safety assessment of DMDM hydantoin declared it as “safe as a cosmetic ingredient in the present practices of use.” Even the Cosmetics Directive of the European Union also has approved this ingredient as a preservative in cosmetics and personal care products at a maximum concentration of 0.6 percent.

But as we have seen with the experiences of the people involved in the lawsuit, there is no way to know those who will react to formaldehyde or not. It would be better to avoid it totally, especially if you have had eczema or any other skin condition in the past.

Also among the debated DMDM hydantoin side effects is that it can be mutagenic in large quantities, causing changes in some human body cells. It is also said that it can cause cancer.


As of now, it is not very clear if DMDM hydantoin on hair is a harmful thing or not. Many experts have different opinions regarding the DMDM hydantoin side effects on people. It might take years of extensive research before we can conclude that it’s safe or if it’s one of the skincare ingredients to avoid in our routines.

While using products with DMDM hydantoin, some people may experience some side effects while others might not. Thankfully, there are a lot of beauty and skincare products in the market without DMDM hydantoin. So just to be sure, we think it’s best to choose a shampoo without DMDM hydantoin.

Read more on: skin