A summer of pool days and ocean swims is rough on hair in a way most people don't notice until it's already dry, brittle, and tangled. Chlorine and salt water both pull moisture out and rough up the surface of every strand, and the damage stacks up swim after swim. The good news: a two-minute habit before you get in the water prevents most of it. This post covers exactly what to do, before and after.
The short answer
To protect hair from chlorine and salt water, soak it with clean water and coat it in a light oil before you swim, so it absorbs less pool or sea water. Rinse and wash soon after getting out, then replace lost moisture with conditioner. The pre-swim barrier step is what prevents most of the damage.
What Does Chlorine and Salt Water Actually Do to Your Hair?
Both chlorine and salt water damage hair by attacking the cuticle, the protective outer layer of each strand, and by pulling moisture out. Chlorine strips away the natural lipids that keep the cuticle smooth and water-resistant, leaving the surface rough, more porous, and prone to tangling. Salt water draws water out of the strand through simple osmosis, leaving hair dry, stiff, and brittle.
The effect is measurable, not just cosmetic. In a study of elite competitive swimmers, 61 percent showed visible hair discoloration and chemical changes to the strand, compared to zero percent in non-swimmers, with the swimmers' hair showing lower sulfur content, a sign of degraded keratin (Nanko et al., Dermatology, 2000, via PubMed). That's heavy, repeated exposure, but it shows clearly what chlorinated water does to the strand over time.
For most people the result is subtler but real: hair that feels drier, looks duller, tangles more, and loses moisture faster as the cuticle gets rougher and more porous over a summer.
How Do You Protect Your Hair Before You Get in the Water?
The single most effective thing you can do happens before you swim, not after. Hair absorbs water like a sponge, so the trick is to fill it up with clean water first and add a barrier, so there's less room for chlorinated or salt water to soak in.
Do these two things right before you get in:
- Soak your hair with clean water. Wet hair from the tap or a shower fully before swimming. Hair that's already saturated with clean water absorbs far less pool or sea water.
- Coat it in a light oil. Smooth a few pumps of a lightweight oil over your hair, focusing on the mid-lengths and ends. The oil adds a water-resistant layer over the cuticle, the same logic behind using oil as a pre-wash barrier treatment. A light oil like the Growth & Strengthen Hair Oil works because it coats without feeling heavy or washing straight off.
If you have long hair, tying it up in a loose braid or bun after this adds one more layer of protection by reducing how much surface area is exposed and how much it tangles in the water.
What Should You Do to Your Hair Right After Swimming?
Rinse and wash as soon as you reasonably can. The longer chlorine and salt sit on your hair, the more they dry it out and the harder the residue is to remove. Don't let pool or ocean hair air-dry and sit for hours.
Here's the order that works:
- Rinse with clean water first, even before you can get to a real shower. A poolside rinse removes a surprising amount of chlorine and salt on its own.
- Wash with a gentle, sulfate-free shampoo, focusing on the scalp to lift residue without stripping what moisture is left. Our scalp-first cleansing method is the approach here. A harsh, sulfate-heavy clarifying shampoo every single swim will leave hair drier than the chlorine did.
- Always follow with conditioner, because both chlorine and salt leave the cuticle raised and thirsty. This step puts moisture and slip back so hair doesn't tangle and snap as it dries.
That's it. Barrier before, rinse and replenish after. Most swim damage is preventable with this loop.
How Do You Rebuild Moisture Across a Summer of Swimming?
Even with a good pre- and post-swim routine, a full summer of swimming gradually raises the hair's porosity, meaning it loses moisture faster than it can hold it. So alongside the per-swim routine, build in deeper moisture on a weekly basis.
Once a week, give hair a longer conditioning session and let it sit a few minutes before rinsing, rather than the usual quick rinse-out. If your hair already runs dry or has gone more porous over the summer, our high porosity hair guide covers how to keep moisture locked in.
Between washes, a small amount of oil on the ends keeps them from going crispy. Summer hair care is really just being a little more deliberate about replacing what the water keeps pulling out.
How the Mimane Glow Routine Fits Into Your Summer Swim Days
The full summer swim routine maps cleanly onto the Glow Kit, which is why it's an easy one-and-done for the season. The hair oil is your pre-swim barrier, the shampoo is your gentle post-swim cleanse, and the conditioner is the moisture you put back afterward.
We designed the oil to be light enough to layer this way. A heavy oil would feel greasy under a swim cap and wouldn't rinse cleanly afterward, while a barely-there serum wouldn't hold up in the water. The Growth & Strengthen Hair Oil sits in the middle: enough of a coat to act as a real barrier, light enough that it absorbs and rinses without buildup. That balance is the whole point, and it's the same reason it works for everyday use, not just swim days.
Pairing the gentle sulfate-free shampoo with the conditioner matters here too. The fastest way to wreck summer hair is to strip it with a harsh clarifying wash after every swim. A gentle cleanse plus real conditioning protects the moisture you're working to keep.
Does This Work for All Hair Types?
Yes, the barrier-before, replenish-after approach works for every hair type, but a few groups need it most.
- Color-treated hair is the most vulnerable. Chlorine accelerates fading and can shift tone, so the pre-swim oil barrier matters even more.
- Dry, curly, or coily hair is already more porous and loses moisture fast, so it dries out quickest from chlorine and salt.
- Fine hair tangles and feels brittle quickly after swimming, though it needs a lighter hand with the oil so it doesn't go limp.
The routine doesn't change much by hair type; the amount of oil and how often you deep-condition does. Drier and more porous hair leans heavier on moisture; fine hair keeps it light.
FAQ
Does chlorine really damage your hair, or is that a myth? It genuinely damages hair. Chlorine strips the cuticle's protective lipids, raises porosity, and degrades keratin with repeated exposure, leaving hair drier, rougher, and more prone to tangling and breakage.
Is salt water or chlorine worse for hair? They damage hair differently. Chlorine chemically strips and roughens the cuticle, while salt water dehydrates the strand through osmosis. Both dry hair out, and the same protect-before, replenish-after routine handles both.
Should I put oil in my hair before swimming? Yes. Wetting hair with clean water and coating it with a light oil before swimming creates a barrier so it absorbs less chlorinated or salt water. It's the single most effective preventive step.
How soon should I wash my hair after swimming? As soon as you reasonably can. A clean-water rinse poolside helps immediately, and a gentle shampoo and conditioner soon after removes residue before it has time to dry the hair out further.
Why does my blonde or light hair turn green in pools? Green tones come from copper in the water binding to hair, not the chlorine itself, though chlorine helps the process along. A pre-swim barrier and prompt washing reduce it.
Do I need a special swimmer's shampoo? Usually not. A gentle sulfate-free shampoo plus consistent conditioning protects moisture better than a harsh clarifying shampoo used after every swim, which can leave hair even drier.
The Wrap
Summer hair damage isn't really about the pool, it's about what you do before and after you get in. Saturate and coat your hair going in, rinse and replenish coming out, and deep-condition once a week, and chlorine and salt lose most of their bite. The Glow Kit covers all three steps, so it's the simplest way to swim all summer without paying for it in dry, brittle ends.
Heading to the pool this week? Put the oil on before you go in. Shop the Glow Kit →
