[ Blonde and aftercare ]
Hair chelation: what it is and why it comes before bleaching
What is hair chelation and why is it done before lightening?
A chelating hair treatment removes the metals and mineral build-up that settle on hair from water: calcium, magnesium, iron and copper. It's done before lightening because metals get in the way of even bleaching, dry the hair out under the powder, add extra yellow and stop reconstruction actives from getting inside. Chelation is part of every service I do.
How chelating agents work
The word comes from the Greek for "claw". A chelating agent is a molecule that grips a metal ion from several sides and holds it in a soluble complex. Once that happens, the metal can be rinsed away with water instead of staying on the hair.
Professional chelating products use various ingredients: EDTA, EDDS, citric acid and others. They bind the calcium, magnesium, iron and copper ions that have accumulated in the keratin. The product is applied, left for a set time and rinsed, sometimes in several stages. During the treatment the client doesn't feel anything in particular, but afterwards the hair often feels softer and less rough, especially if the water at home is hard. The step usually doesn't take long and happens before the main work, so it doesn't need a separate appointment.
Why metals are a problem during lightening
Bleach works through hydrogen peroxide in an alkaline environment. The peroxide oxidises melanin and the hair gets lighter. But copper and iron act as catalysts: in their presence peroxide breaks down faster and forms hydroxyl radicals. These are highly reactive particles that damage not only pigment but the hair's protein as well.
Research by Marsh and colleagues showed that copper accumulated in hair increases damage during bleaching. In practice colourists see this as "hot spots": areas where the lightener acted too aggressively, where the hair turned brittle or lifted unevenly. That's where the extra yellow comes from, the patches, the feeling that the hair "burnt" in one place even though the mix was applied evenly. Chelating before lightening removes some of these metals and lowers that risk. It can't remove it completely, but the difference is noticeable.
Hard water and hair: what's actually known
I want to be honest here. The evidence on how hard water affects hair strength is mixed. Some studies find that hair washed in hard water becomes more brittle and coarse to the touch; others see no significant difference in strength. So I won't tell you that hard water on its own will ruin your hair.
What can be said with confidence: calcium and magnesium from hard water settle on the surface, make hair duller and drier to the touch, stop shampoo lathering properly and keep conditioning products from spreading evenly. On lightened, porous hair the deposits build up faster. And where pipes are old, iron and copper join the calcium, and those do directly affect lightening.
How chelation differs from a clarifying shampoo
I often hear: "But I use a clarifying shampoo once a week." A clarifying shampoo contains stronger surfactants. They're good at removing sebum, styling residue, silicones and some dirt. But surfactants don't remove minerals bound to the keratin, because those aren't oil or a film sitting on the surface.
Some clarifying shampoos do contain chelating additives, so they can have some effect. But professional chelation in the salon uses a dedicated product with enough concentration and contact time, done right before lightening or toning. They're different jobs, and one doesn't replace the other. Between visits you can use a chelating product at home if your water is very hard, but don't overdo it: these can be drying too.
Why chelation is part of every service I do
I include chelation in all my services: Airtouch, relief, contouring and toning. There are several reasons. Metals from water interfere with bleaching and make it less predictable. Under the powder they dry the hair out. They add excess yellow that then has to be covered with toner, and toner holds less well on that hair. And they block reconstruction actives, meaning part of the treatment never reaches where it's needed.
Minerals build up every day with every wash, so chelation isn't a one-off. It makes sense to do it each time before a chemical service. I've written about how blonde reacts to the sea and pools, where there are even more metals, in blonde hair after the sea, and about the link between metals and a yellow base in brassy yellow after bleaching.
How to book
I don't sell chelation as a separate service; it's already included in each one. Toning with reconstruction costs from 700 UAH, Airtouch from 3,200 UAH, relief from 2,500 UAH, contouring from 1,000 UAH. I work with the professional brand Viart.
Message me on Telegram. Send a photo of your hair in daylight and, if you know, tell me what kind of water you wash it in and whether you ever see greenish or reddish tints. That helps me gauge how much metal might be in your hair.