About Highlighting
Highlighting lightens selected sections of the hair to add depth, brightness and dimension. A colourist works through the hair using foils, a freehand painting technique such as balayage, or a highlighting cap, applying a lightener or bleach to the pieces being lifted while leaving the rest of your natural colour in place. Depending on the look you want, highlights can be fine and subtle for a sun-kissed effect, or bolder and higher-contrast for a more dramatic finish, and the placement can be tailored to frame your face or brighten the ends. Many appointments finish with a toner or gloss to refine the shade and remove unwanted warmth. Because highlighting usually involves a lightening product, the health of your hair and scalp matters, so a good colourist will assess your hair's condition and colour history first. Results build well when the service is planned around your natural base, your previous colour and how much lift is realistic in one sitting. It is a popular, generally low-risk salon treatment when carried out by a trained colourist, but sensible preparation and honest expectations help you get a result you are happy with and protect the long-term condition of your hair.
On the day, and after
During the treatment
Your colourist will usually start by talking through the look you want and checking your hair's condition and colour history. The lightener is then applied to the chosen sections, either wrapped in foils, painted freehand and left open, or pulled through a cap. You may sit with the product processing for a while, sometimes under heat, and your colourist will check the lift regularly rather than leaving it to a fixed time. Once the desired level is reached, the hair is rinsed, and a toner or gloss is often applied to neutralise brassiness and perfect the shade. Most appointments finish with a conditioning or bond-building treatment, a shampoo and a blow-dry so you can see the result. A full head of highlights takes longer than a partial or face-framing set. Throughout, tell your colourist if you feel any stinging, burning or discomfort on the scalp so they can act promptly.
How it feels
During processing you may feel a gentle warmth from the lightener, a slight tightness where foils sit close to the scalp, and the weight of the foils themselves. Some people notice a mild tingling, but you should not feel genuine stinging, burning or pain, and any of these means the product should be checked or rinsed straight away, so always tell your colourist. Toner tends to feel cool and comfortable. The rinse and any bond or conditioning treatment usually feel pleasant. Afterwards your hair may feel a little drier or more textured until it is conditioned, which is normal for freshly lightened hair.
Results and maintenance
How long highlights look their best depends on the technique, how much lift was done and how you care for your hair. Foiled highlights that start near the roots show regrowth sooner, often around every six to eight weeks, while balayage and painted, lived-in looks can stretch to around three to four months because the grow-out is softer. Toner and gloss fade faster than the lightening itself, so a refreshing toner between full appointments can revive brightness and control brassiness. Using colour-safe, gentle products, deep conditioning regularly, minimising heat and protecting your hair from sun, chlorine and salt water all help the result last and keep the tone true. Your colourist can tailor a maintenance schedule to your budget and how much upkeep you want, and lower-maintenance placements are worth discussing if you prefer fewer visits. Regular trims keep the more porous ends looking healthy as the colour grows out.
Before and after your appointment
Before your appointment
Book a consultation, or discuss your goals when you arrive, so your colourist can see your natural base, any existing colour or box dye, and the condition of your hair before deciding what is achievable. Bring reference photos and be honest about home colour, henna or previous lightening, because these affect how evenly the hair lifts and whether the target shade is realistic in one visit. Arrange your allergy alert (patch) test in good time if a toner, gloss or tinted product will be used, typically at least 48 hours beforehand. Coming with hair that is not freshly washed on the day is often fine, as a little natural oil can help protect the scalp, but follow your salon's specific advice. Avoid booking straight after a fresh keratin or other chemical service, and mention any recent illness, medication, scalp conditions or sensitivity. If your hair is already dry or compromised, ask about a strengthening plan first so the lightener works on healthier hair.
Aftercare
For the first couple of days, try to avoid washing your hair too soon so the toner and cuticle can settle, then switch to a gentle, sulphate-free shampoo and a conditioner suited to lightened hair. Lightened strands are more porous, so a regular deep-conditioning or bond-building mask helps keep them strong and glossy. Colour-safe and purple or blue toning products can help hold your shade and control unwanted warmth between visits, but use toning shampoos sparingly to avoid over-cooling the tone. Protect your hair from excessive heat by using a heat protectant and keeping tools at a moderate temperature, and shield it from strong sun, chlorine and salt water, which can fade and dry the colour. Trims help keep porous ends looking healthy. If your scalp feels irritated after the appointment, keep the area gentle and clean, and seek advice from your salon or a pharmacist. Contact your colourist if the tone or condition is not what you expected.
Highlighting has essentially no downtime, and most people return to normal activities straight away. Your hair may feel slightly drier or more porous at first, which good conditioning usually settles within a few washes. If a lightener has been used close to the scalp, a little tenderness or sensitivity can occasionally occur and normally eases quickly. Any genuine burning, blistering, weeping or significant breakage is not expected and should prompt you to contact your salon and, if the skin is affected, seek medical advice. Otherwise, no recovery period is needed.
Safety and medical considerations
Safety essentials
The most important safeguard is a trained, insured colourist who assesses your hair and scalp before applying any lightener. Lightening products are strong chemicals, so correct mixing, timing and placement matter, and the person doing your hair should monitor the lift rather than leaving it unattended. Bleach applied to a broken, irritated or freshly shaved scalp raises the risk of stinging and burns, so flag any cuts, sores or scalp conditions beforehand. If a toner, gloss or any product containing dye is used, an allergy alert test carried out in advance is essential, because reactions to colourants can be serious. Overlapping lightener onto previously bleached hair, or trying to force too much lift in one sitting, is a common cause of breakage, so trust your colourist if they advise a gradual approach. Always speak up during the appointment if you feel heat, stinging or pain on the scalp so it can be rinsed promptly.
Medical considerations
Highlighting is a cosmetic service rather than a medical treatment, but some health factors are worth raising. Tell your colourist about scalp conditions such as psoriasis, eczema or dermatitis, any open sores or recent scalp procedures, and a history of reactions to hair colour, henna or the temporary tattoo ingredient PPD, as these can indicate a higher risk of an allergic response. If you are pregnant or breastfeeding, highlighting is generally considered low risk because the lightener is mostly kept away from the scalp, but you may prefer to discuss it with your midwife or GP and let your colourist know. Mention medications or treatments that affect skin sensitivity or healing. If you have ever had a serious allergic reaction, or experience swelling, breathlessness or a widespread rash after a hair product, seek urgent medical care and avoid further colour until you have spoken to a GP or a qualified dermatologist. When in doubt about your suitability, ask your colourist and your GP before booking.
Patch testing
If your highlights include a toner, gloss or any tinted product, an allergy alert (patch) test is strongly recommended, usually at least 48 hours before your appointment and following the manufacturer's instructions. This matters for your safety and for UK liability: many insurers will not cover a colourist who skips a required test, so its presence protects both you and the salon if a reaction occurs. Importantly, a patch test is not fully conclusive, and sensitivities can build over time, so a previous clear result does not guarantee future safety, which is why reputable salons retest periodically and whenever the product or your circumstances change. Pure lightener applied only to the hair lengths may not need the same test, but tell your colourist about any past reaction so they can decide on the right checks and record your consultation. A strand test may also be used to see how your hair lifts.
Knowing a good practitioner
Green flags
A good colourist gives you a proper consultation, checks your natural base, colour history and hair condition, and is honest about what is realistically achievable in one visit. They arrange an allergy alert test where a toner or tinted product is involved, keep clear records, and explain their plan and any risks in plain terms. Expect careful, monitored application, regular checks on the lift rather than a rigid timer, and a willingness to advise a gradual approach to protect your hair. Clean tools, tidy sectioning, bond-building or conditioning support, and a toner to refine the finish all signal care. They should welcome your questions, encourage you to speak up about any scalp discomfort, give you tailored aftercare advice, and hold appropriate professional qualifications and insurance.
Red flags
Be cautious if a salon offers to use a toner or tinted product with no allergy alert test and no questions about your history, or dismisses a previous reaction to colour. Rushing you into maximum lift in a single visit on already-bleached or fragile hair, or overlapping bleach onto previously lightened sections, risks breakage and is a warning sign. Applying lightener to a cut, sore or irritated scalp, ignoring you when you report stinging or burning, or leaving product on far beyond the point of even lift are all concerns. Vague answers about the products used, no consultation, unrealistic promises of platinum results from a dark base in one sitting, and poor hygiene or reused, dirty tools should all give you pause. Any severe scalp pain, blistering or significant hair snapping means the service should stop.
Questions to ask
- Based on my natural base and colour history, how much lift is realistic in one visit and will I need more than one appointment?
- Will you use a toner or tinted product, and do I need an allergy alert test beforehand?
- How will you protect the condition of my hair, and do you offer bond-building or conditioning support?
- Which technique do you recommend for the look I want, foils, balayage or a cap, and why?
- How often will I need to come back for maintenance and roughly what will that cost?
- What are your qualifications and are you fully insured for colour services?
Frequently asked questions
Will highlighting damage my hair?
Any lightening changes the hair's structure and can leave it more porous, but a skilled colourist minimises this by choosing the right strength, monitoring the lift and using bond-building or conditioning support. Good aftercare, gentle products and regular masks help keep highlighted hair strong and glossy.
Do I really need a patch test just for highlights?
If your service includes a toner, gloss or any tinted product, an allergy alert test is strongly recommended, usually at least 48 hours before, because reactions to colourants can be serious. Pure lightener on the lengths may not need one, but always tell your colourist about any past reaction so they can decide.
How is highlighting different from balayage?
Balayage is one way of highlighting, a freehand painting technique that gives a soft, blended, lived-in look. Traditional highlights are usually wrapped in foils for a more uniform, brighter result. Your colourist can recommend which suits your hair and the finish you want.
Can I get platinum highlights from dark hair in one visit?
Often not safely. Lifting dark hair to a very pale result can take more than one appointment to protect the condition of your hair. A responsible colourist will be honest about what is realistic in one sitting rather than risk breakage by forcing too much lift.
Is it safe to highlight my hair while pregnant?
Highlighting is generally considered low risk in pregnancy because the lightener is mostly kept off the scalp, but many people prefer to discuss it with their midwife or GP first. Let your colourist know so they can take extra care and arrange any allergy alert test.
This guide is general information, not medical advice. Speak to a qualified practitioner, and to your GP if you have a medical condition, before booking.