Laser Treatment for Pigmentation: Preparation, Aftercare and What a 30 % Vitamin C Serum Really Does

Age spots, melasma or dark marks after acne: pigmentation disorders are among the most common reasons for facial laser treatment. How good the result is and how long it lasts depends not only on the device but very much on preparation and aftercare. And the popular 30 per cent vitamin C serum also has its place – though a different one from what many people think.

Get it checked first, then laser

Not every brown spot is harmless. Before any treatment, a dermatologist should assess the spot with a dermatoscope. An early form of melanoma, lentigo maligna, can resemble an age spot – a laser would only lighten it superficially and delay the diagnosis.

The type of pigmentation disorder is just as important:

• Age spots (solar lentigines) usually respond well; one or two sessions are often enough.
• Melasma is more difficult: lasers are only considered when sun protection and creams are not sufficient. Relapses are common, and too much energy can make the patches worse.
• Dark marks after inflammation often fade by themselves with time and sun protection; lasers are used cautiously here.

A detailed overview of forms, causes and treatments can be found in our encyclopaedia under Pigmentation disorders of the skin.

Which lasers are used?

Pigment lasers emit extremely short pulses of light that are absorbed by melanin and break it up. Commonly used are Q-switched lasers (such as Nd:YAG at 532 or 1064 nanometres), picosecond lasers and fractional lasers. IPL technology is not a laser but is also used for age spots. In darker skin (skin types IV to VI), the risk of darkening is higher; longer wavelengths, low energy and a test patch are then preferred. In Germany, laser treatments of the skin may, under the NiSV radiation protection ordinance, only be carried out by appropriately qualified doctors.

Preparation: the four weeks before

• Avoid the sun: no sunbathing, no sunbeds, no self-tanner. Tanned skin absorbs laser energy in an uncontrolled way, making burns and marks more likely.
• Daily sun protection with a sun protection factor of 50 – for melasma ideally tinted with iron oxides, because visible light also stimulates pigment.
• Brightening skincare such as niacinamide, azelaic acid or tranexamic acid can – after discussion with your doctor – be started beforehand. If there is a tendency to darkening, a medically prescribed pre-treatment is sometimes used.
• Disclose your medicines: especially isotretinoin for acne, photosensitising antibiotics and St John’s wort.
• Mention any history of cold sores; for treatments around the mouth, a preventive tablet may be advisable.

The last week before the appointment

About three to seven days beforehand, irritating active ingredients are paused: retinoids such as retinol, fruit acids such as glycolic acid, peels and high-strength vitamin C. On the day of treatment, the skin should be calm, not red and uninjured. On the day itself, come to the practice without make-up.

After the treatment: step by step

Days 0 to 3: redness, slight swelling and a feeling of warmth are normal. The treated spots often darken at first and form fine crusts. Cooling with clean compresses, mild soap-free cleansing and simple, fragrance-free skincare with ceramides or dexpanthenol are helpful. After ablative lasers, follow your doctor’s wound care instructions.

Days 4 to 14: do not pick or rub off the crusts – they usually come off by themselves after one to two weeks. No peeling, no sauna and no exercise with heavy sweating in the first few days. During the day, use mineral or well-tolerated sun protection with SPF 50, reapplied every two hours if necessary, plus a hat or cap.

From week 3: once the skin has fully healed and is no longer red, brightening and antioxidant ingredients can gradually be reintroduced – first mild ones such as niacinamide, later vitamin C and retinoids. Strict sun protection continues for at least four to eight weeks, and permanently in melasma.

Warning signs: blisters, weeping or pus-filled areas, increasing pain or spots that become darker rather than lighter after a few weeks should be checked at the treating practice.

30 per cent vitamin C serum: what’s behind it?

Vitamin C in the form of L-ascorbic acid is one of the best-studied antioxidants for the skin. It neutralises free radicals produced by UV radiation, weakly inhibits the pigment-forming enzyme tyrosinase and is required for the formation of collagen. On pigment spots it acts mildly and slowly – more as a companion than as the main treatment.

More is not automatically better. Older studies on skin absorption showed that tissue levels rise up to a concentration of about 20 per cent and do not increase further above that. According to current knowledge, a 30 per cent serum therefore brings no additional benefit but causes irritation more often: stinging, redness and dryness are typical, especially with sensitive skin or rosacea. For most people, 10 to 20 per cent is a sensible range.

What matters in the formulation:

• L-ascorbic acid only works well in an acidic environment (pH of around 3.5 or below) – which explains the tingling when it is applied.
• It oxidises easily. A serum that has turned yellow-brown has lost its effect. Opaque bottles, airless dispensers and cool storage help.
• Combining it with vitamin E and ferulic acid stabilises vitamin C and, in studies, enhanced protection against UV-induced skin damage.
• Derivatives such as magnesium or sodium ascorbyl phosphate, ascorbyl glucoside or ethyl ascorbic acid are milder and more stable but less well studied.

How to use it: in the morning on cleansed, dry skin, followed by moisturiser and always sun protection. Vitamin C does not replace sun protection but complements it usefully. Test a new, high-strength product on a small area first and use it only every other day at the beginning.

Around the laser treatment: pause it about three to seven days before treatment and only restart once the skin has fully healed – usually after one to two weeks following non-ablative lasers, often considerably later after ablative ones. If you want to restart quickly after the laser, it is better to begin with a lower concentration.

Other active ingredients at a glance

• Sun protection (SPF 50, broad-spectrum, tinted for melasma): the single most important measure – before, during and after any treatment.
• Niacinamide (usually 2 to 5 per cent): inhibits the transfer of pigment to skin cells, strengthens the skin barrier and is well tolerated; one of the first ingredients that can be used again after laser treatment.
• Azelaic acid: has a brightening and anti-inflammatory effect and is proven in melasma and post-acne marks; higher concentrations are available as medicines.
• Tranexamic acid (topical): increasingly found in serums for melasma; the evidence is promising but still limited.
• Alpha-arbutin and kojic acid: cosmetic tyrosinase inhibitors with a mild effect; a maximum concentration applies to kojic acid in the EU.
• Retinoids: accelerate skin renewal and help to remove pigment; they are irritating and increase sensitivity to light, so they should be paused around laser treatment.
• Fruit acids (glycolic, mandelic, lactic acid): loosen keratinised cells and superficial pigment; pause before and immediately after laser treatment.
• Ceramides, dexpanthenol, glycerin: support the barrier during the healing phase.
• Hydroquinone: not permitted in cosmetics in the EU; may only be used as a medically prescribed medicine and for a limited period.

What is best avoided

• “Bleaching creams” from the internet or markets: they may contain mercury, undeclared corticosteroids or impermissible amounts of hydroquinone and can damage the skin permanently.
• Too many strong active ingredients at the same time: irritated skin is prone to new dark marks.
• Laser treatments in high summer or shortly before a sunny holiday.

Conclusion

A pigment laser can effectively remove age spots in particular. The keys to a good and lasting result are an assessment by a specialist, consistent sun protection and calm, barrier-friendly skincare around the treatment. Vitamin C is a useful component for the period afterwards – a concentration of 10 to 20 per cent is sufficient; according to current knowledge, 30 per cent brings no added value but more irritation.

Note: This article is for general information only and does not replace advice from a dermatologist or other doctor. It does not contain product recommendations from individual manufacturers.

Sources

• AWMF-S2k-Leitlinie Lasertherapie der Haut (Reg.-Nr. 013-095), Deutsche Dermatologische Gesellschaft, 2022
• Laser therapy in the treatment of melasma: a systematic review and meta-analysis (PubMed)
• Management of Melasma: Laser and Other Therapies – Review Study (PMC)
• Pinnell S. R. et al.: Topical L-ascorbic acid: percutaneous absorption studies. Dermatologic Surgery 2001; 27(2): 137–142
• Lin F.-H. et al.: Ferulic acid stabilizes a solution of vitamins C and E and doubles its photoprotection of skin. Journal of Investigative Dermatology 2005; 125(4): 826–832
• Verordnung (EG) Nr. 1223/2009 über kosmetische Mittel (Regelungen zu Hydrochinon und Kojisäure)