Medically reviewed by Vicky Davis, FNP
Written by Our Editorial Team
Last updated 10/26/2021
Thinking about bleaching your hair? If so, there are a few things you should know.
Most importantly, yes, it does damage your hair. But that doesn’t mean you can’t do it. You just need to know how to add nourishment back into your strands.
That’s what we’re digging into today. What, exactly, does bleach do to damage your hair? Once the damage is done, how can it be repaired? What tips and tricks do the pros recommend?
If you’re thinking of bleaching your hair, chances are your goal is to lighten it — and bleach is a very effective way of doing that. Bleach is a fast way to remove pigment from your hair.
When applied to your hair, bleach opens the hair shaft and breaks down pigment molecules. When you wash the bleach out, those pigments go with it and leave you with lighter hair.
At the same time, it weakens the hair by breaking down the fatty acids on the shaft. This can leave hair feeling dry and brittle.
One study done on rats found that after bleaching their hair, it was weakened. It is, of course, worth noting that because this study was conducted on rats, it may not be exactly true for humans.
However, we think it’s safe to assume the results would probably be at least similar in humans.
Another study used a microscope to look at the hair shaft after bleaching and found there was damage to the structure of the hair.
If you do decide to bleach your hair, it’s important to know ways you can add moisture and shine back into your strands — since those are the things bleach can take away.
Since bleach strips important nutrients and proteins out of your hair, you’ll want to incorporate some habits into your routine that support hair health.
If you have bleached strands, the types of products you use matter. Consider using a shampoo and conditioner formulated to thicken hair.
Her’s thickening shampoo is made with a natural ingredient called saw palmetto. Research suggests it can potentially reduce hair loss.
One study, for instance, compared the hair loss medication finasteride with saw palmetto. Finasteride was found to be most effective in reducing hair loss, but saw palmetto was also effective.
Oh, and don’t skip the conditioner! The whole point of a conditioner is to replace moisture. They can also increase shine and volume.
There are a variety of conditioners to choose from — from ones intended for daily use, to leave-in treatments and deep conditioning masks.
Using one after you shampoo is good for maintenance. Deep conditioners are more concentrated and are intended to be left on your hair for a longer period of time before washing out.
Interested in a leave-in conditioner? They are meant to be applied to wet hair after a shower to moisturize and detangle hair.
Remember how we said bleach strips fatty acids from your hair? Making sure you’re getting enough omega-3 fatty acids can help boost hair health.
One study looked at 120 women over the course of six months and found that omega-3 and omega-6 — notable antioxidants — can be useful in improving hair density.
A good way to incorporate these into your routine is through diet. Foods that contain them include:
Fish (like salmon, mackerel and tuna)
Nuts and seeds (like chia seeds and walnuts)
Plant seed oil (like flax seed oil)
If you have a hard time getting enough into your diet, you can consider an omega-3 supplement.
From cooking to beauty benefits, coconut oil is often praised for its many uses.
When it comes to using it in your hair care regime, it is known to have antibacterial and antifungal properties, both of which can help protect your strands.
Coconut oil also is full of fatty acids — and you already know those promote healthy hair.
Another benefit: it penetrates deep into the hair shaft, which can help prevent breakage.
Another oil you should know about is argan oil, which is also rich in fatty acids. This type of oil is touted as a worthy adversary against dry hair.
Recently, biotin supplements have become all the rage. They’re all over social media, with influencers swearing that they make hair healthier. But do they?
There’s simply not enough research to support these claims. Beyond that, you probably don’t need a biotin supplement, as you most likely get enough from your diet.
All of this said, there is early research linking biotin to hair growth.
Here’s another supplement you’ve likely seen hocked on Instagram. Collagen is a protein that is naturally present in mammals.
It’s hugely important in skin, hair, muscles, nails and connective tissue.
It may surprise you to know that it actually makes up 30 percent of your body’s protein mass.
But, like with biotin, a heck of a lot more research is needed to support whether or not collagen supplements can boost hair health. See more details in our collagen and hair guide.
There was one small study done that centered around 15 women who all reported having thinning hair.
Some of the women were assigned a collagen supplement, others were given a placebo. All the women took these supplements twice a day for six months.
After half a year, the women who took collagen said they noticed that their hair was shinier.
If you’re looking to go from dark hair to blonde hair, you’ll have to use bleach. Or perhaps you want to lighten your hair so you can then dye it a bold color — hello, blue strands. Whatever your reason, you should know that using hair bleach can damage your locks.
When you use bleach, this chemical process seeps into hair follicles and can make your hair dry and brittle.
The level of damage this can do varies and really depends on the condition of your hair and your hair type to begin with.
Because of this, you’ll want to give bleached hair a good deal of TLC. That can mean everything from using a hair mask (try one for color-treated hair!) on the regular to considering various supplements.
It’s also worth noting that if you do want to bleach your hair, you should go to a professional hair stylist. They will know how to prevent permanent damage during the hair bleaching process.