In short. Light, grey and red hair, some medicines and some skin conditions make either option the wrong tool, and the assessment should say so before a course begins.
Key points
- Where neither option suits the hair, the assessment has still done its job.
- A patient told plainly that the hair will not respond has been saved a course of sessions, and one told that part of the area will respond has been given an honest expectation rather than a promise.
Both of these options are tools, and a tool is only useful when it suits the material in front of it. For a group of patients neither instrument is suitable, and establishing that at the assessment is more useful than discovering it at the end of a course.
Hair without the pigment
White, grey, red and very light hair contains little of the pigment that carries the light into the follicle, so there is nothing for either instrument to act on. This is the clearest case in which both options are the wrong tool, and it is not solved by choosing one instrument over the other or by adding sessions. Where only some of the hair in an area is grey, the remainder can still be treated, and the result is a partial one that should be described as partial.
An active skin problem in the area
An active infection, broken skin or an untreated skin condition in the treated area is a reason to postpone, because treatment over inflamed or infected skin risks making it worse. A mole in the area is avoided rather than treated. These are delays rather than refusals, and the plan is reconsidered once the skin has settled.
Saying so is the useful part
Where neither option suits the hair, the assessment has still done its job. A patient told plainly that the hair will not respond has been saved a course of sessions, and one told that part of the area will respond has been given an honest expectation rather than a promise.
Medicines that change the risk
Some medicines make the skin sensitive to light, and that changes the margin between a setting that works and one that damages. This is a matter for the assessment rather than for the patient to act on alone, and no prescribed medicine should be stopped because of a planned light treatment without speaking to the prescriber. What the treating team needs is to know everything being taken, including anything bought without a prescription.
Where the hair is a symptom rather than the problem
Hair growth can be driven by a hormonal condition, and treating the hair while leaving the condition unassessed is a partial answer: the hair can return while the driver remains. Where the pattern or the timing of the hair growth suggests a hormonal cause, that is assessed rather than treated with sessions. And where the concern is hair loss rather than unwanted hair, neither of these options is part of the answer.
Where neither option is the right tool
- White, grey, red or very light hair, which does not have the pigment either option depends on.
- An active skin infection, broken skin, an untreated skin condition or a mole in the treated area.
- Hair growth driven by an unassessed hormonal condition, or hair loss rather than unwanted hair.
Neither of these options is suitable for every patient. Being told that light treatment is the wrong tool is a finding about your hair, and it is more useful than a course that could not have worked.
Frequently asked questions
What if my hair is white or grey?
Neither option is suitable, because both depend on the pigment in the hair to carry the light into the follicle, and white and grey hair contains little of it. This is not a matter of choosing the stronger instrument or having more sessions. Being told so is a finding rather than a refusal, and it saves a course that could not work.
Which medicines matter?
Some medicines make the skin sensitive to light, and that is a conversation for the assessment rather than something to act on alone. Do not stop a prescribed medicine because of a planned light treatment without speaking to the clinician who prescribed it. What matters is that the treating team knows everything you take, including anything you buy without a prescription.
Can I be treated if I have a skin condition in the area?
Some skin conditions are made worse by light treatment and are settled first, and an active infection or broken skin in the area is a reason to postpone. A mole in the treated area is avoided rather than treated. The assessment is where that is established, and it is a reason to arrange one rather than to book a session.
Risks & Limitations
- No result can be guaranteed, and hair reduction is not the same as permanent hair removal.
- Burns, blistering and pigment change are possible with both options, and are more likely when the settings do not match the skin or the skin has been tanned recently.
- Hair returns over the months after a course, and both options need maintenance rather than one course.
- Neither option works well on light, grey, red or white hair, because both depend on pigment in the hair.
When to Seek Care
- A blister, or skin that is weeping or breaking down in the treated area.
- Pain that is increasing rather than settling, or redness that is spreading.
- A change in skin colour — lighter or darker — that is spreading rather than fading.
- Any reaction in the treated area that is worsening rather than settling in the days after a session.
References & Further Reading
- American Academy of Dermatology (AAD) — hair removal and laser safety guidance
- National Institute for Health and Care Excellence (NICE, UK) — relevant guidance
- Cochrane Library — systematic reviews
- Chinese Medical Association Plastic Surgery Branch — clinical guidance
This page is patient education, not medical advice, and it does not cite individual studies. Discuss your own case with a qualified clinician. To arrange an assessment at Chongqing West District Hospital, see Contact & Consultation.