QQ—Can You Use Hydrogen Peroxide to Lift Your Hair Color?

When you think of hydrogen peroxide, the liquid in the brown bottle next to the alcohol in your first-aid kit or local drugstore probably comes to mind. You may also think of all the ways it can be used—to clean a cut, whiten teeth, and, of course, treat acne. But another use that has many reaching for the chemical compound is its hair lightening abilities.

While people have used hydrogen peroxide alone and without expert supervision on their strands in the pursuit of lighter hair, that age-old question remains: Should you use this chemical on your hair at home? Ahead, we get to the bottom of whether or not hydrogen peroxide is safe for your hair with the help of board-certified dermatologist Yoram Harth, MD, certified trichologist and hairstylist Helen Reavey, and Pureology global artistic director Jamie Wiley,

Keep reading to find out everything you need to know about hydrogen peroxide for hair.

What Is Hydrogen Peroxide?

"Hydrogen peroxide is a chemical compound that is used as an oxidizer, bleaching agent, and antiseptic," says Wiley. "[It] will lift the natural melanin from the hair because it works in the hair cortex, the innermost part of the hair that holds the pigment that gives hair its color."

She continues: "Hydrogen peroxide is labeled using a percent or a volume. Both measurements indicate the concentration of oxygen available contained in the bottle. The percentage indicates how much of the content in the bottle is pure hydrogen peroxide [and] the volume indicates the volume of oxygen that is released for every milliliter of content. "

What Is It Used For in Hair?

Salon coloring treatments often involve using hydrogen peroxide's bleaching properties to lighten hair. When applied to hair, hydrogen peroxide penetrates the cortex of hair strands, oxidizing and breaking down melanins, the substance in your body that produces hair, eye, and skin pigmentation).

Potential Side Effects

One of the major drawbacks of hydrogen peroxide is that it permanently alters the hair. "Once this pigment has been removed, your hair color has been permanently altered and cannot be reversed," Reavey explains. "The only way to add color back into the cuticle is by depositing a new color onto the hair." Additionally, she says that continued use of hydrogen peroxide and other chemicals commonly used with it—such as ammonium persulfate and ethyl alcohol—can strip moisture from the hair follicles, leaving your hair and scalp dehydrated.

Dr. Harth adds that because hydrogen peroxide needs to penetrate the outer layer of the hair—the cuticle—hair and scalp damage can be an issue. "The cuticle damage leads to breakage, split ends, and frizz of the hair," he says. "As a potent oxidizing compound, hydrogen peroxide can irritate the scalp, damage the hair follicles, and increase hair loss."

How to Use Hydrogen Peroxide On Hair

Reavey emphasizes that due to the risks, hydrogen peroxide is best used in a salon setting, avoiding at-home treatments. "You should always go to a hair color professional for color and avoid at-home treatments, as these can be especially dangerous when not applied correctly. Misuse can lead to blisters on the scalp and possible scar tissue if not mixed correctly."

During a hair coloring appointment, your stylist may utilize hydrogen peroxide or hydrogen peroxide-based bleaching solutions in several coloring techniques, including single-process, balayage, or highlights.

How Long Does It Take For Hydrogen Peroxide to Lighten Hair?

How fast hydrogen peroxide coloring products lighten your hair primarily depends on hair type thickness, how dark your natural hair color is, and your color goals. Our experts say that, based on these factors, in-salon lightening treatments that involve hydrogen peroxide can vary in time, lasting anywhere from 15 minutes to four hours (and beyond). You may also need to come back for additional sessions to achieve the results you're looking for. If you have questions about how long a service will take or how many treatments you will need to reach your desired color, it's best to consult with your coloring specialist beforehand.

Hydrogen Peroxide vs. Hair Bleach

To understand how hydrogen peroxide and bleach differ, first, you have to understand how hair bleach works. Hair bleaching solutions are a mixture of chemicals that includes an alkaline agent (aka an ingredient like ammonia or ethanolamine that opens the hair cuticle, allowing hair colorants to penetrate the hair strands and form a pigment) and an oxidizing agent that initiates the chemical reaction that changes the hair's color. The most common oxidizing agent found in hair bleach is hydrogen peroxide.

While hydrogen peroxide can be used to lighten hair on its own, the ingredients work much faster and provide a drastic change when paired with the complementary chemicals in hair bleach solutions. However, our experts noted that using hydrogen peroxide on its own may cause less hair damage than using hair bleach. So, when choosing a hair-lightening formula, it's best to keep your hair type and goals in mind and talk through your options with a trusted hair colorist.

Are There Alternatives to Using Hydrogen Peroxide on Hair?

New hair-lightening products that don't use hydrogen peroxide keep rolling out, meaning you've got plenty of alternatives. "A great option is using ammonia-free hair dye when coloring your hair," Reavey tells us. "Ammonia-free hair dyes typically do not need to be formulated with hydrogen peroxide, making it ideal for those with sensitive scalps. Another great option is [asking] your stylist to use coloring techniques like balayage that allow you to go longer periods of time in between colorings without feeling the need for a touch-up. The less frequently your scalp and hair are exposed to peroxide, the better."

Of course, you could also attempt to naturally lighten your hair, with grocery store ingredients like lemon, chamomile, or vinegar. However, these age-old options come with risks, too, and work best when guided by expert supervision.

The Final Takeaway

Hydrogen peroxide is a chemical compound that is used to lighten hair. When applied in a salon by a hair color expert, hydrogen peroxide and hydrogen peroxide-based bleaching solutions are generally safe and can lighten hair in just a few hours. However, when applied improperly or excessively, hydrogen peroxide can cause hair damage such as scalp irritation, follicle damage, and increased hair loss. Before beginning a hair-lightening service, speak with your stylist about any potential questions you have, as well as your hair goals, so they can recommend the best hair coloring plan for you.