Hormonal melasma is triggered when oestrogen and progesterone stimulate melanocyte activity beyond the skin's normal regulatory capacity. Oral contraceptives, hormone replacement therapy, and perimenopause are the three most common hormonal drivers seen in aesthetic practice, each with distinct onset patterns, risk profiles, and implications for treatment planning. UV exposure amplifies but does not cause the condition. The hormonal signal is primary.
Why Hormones Drive Melasma: The Mechanism
Melanocytes in the epidermis and the dermoepidermal junction carry oestrogen and progesterone receptors. When these receptors are activated, tyrosinase activity increases and melanin production accelerates. The same UV-triggered keratinocyte-to-melanocyte signalling pathway that tranexamic acid interrupts is primed and sensitised by hormonal exposure, making UV-exposed skin significantly more reactive in hormonally stimulated patients.
Oestrogen also upregulates melanocortin-1 receptor (MC1R) expression on melanocytes. In parallel, it increases pro-opiomelanocortin (POMC) synthesis in the pituitary, which raises circulating alpha-melanocyte-stimulating hormone (alpha-MSH). The combined effect is a melanocyte system that is functionally on a hair-trigger: normal levels of UV exposure produce abnormal amounts of melanin.
This is why photoprotection is the non-negotiable first step in every hormonal melasma treatment plan. Without it, topical actives are managing a tap that is still running.
Oral Contraceptives and Melasma Risk
The link between combined oral contraceptive pills and melasma has been recognised since the 1960s, and was established in the medical literature in a landmark JAMA case series documenting OCP-induced pigmentation in women with no prior history of the condition. The association has since been replicated across large cohort studies.
A 2025 population-based cohort study published in the Journal of Investigative Dermatology examined melasma incidence across over a decade of follow-up in women using combined oral contraceptives, progestin-only pills, and hormonal intrauterine devices. The findings are instructive for clinical practice.
At one year of follow-up, combined OCP users showed no statistically significant increase in melasma risk over controls. At three years, the picture changed: combined OCP users had a significantly elevated risk, and progestin-only pill users also showed increased risk versus controls. Women using hormonal intrauterine devices did not show the same long-term elevation in melasma risk.
Two clinical implications stand out. First, short-term OCP use may not predispose to melasma, but cumulative exposure is a material risk factor. Second, the delivery method matters: systemic oral exposure carries a different risk profile from localised intrauterine delivery, consistent with the hypothesis that first-pass hepatic metabolism of oral oestrogen amplifies the systemic hormonal signal.
The cohort study controlled for UV exposure data. The authors noted that combined exposure to UV and systemic synthetic oestrogen was associated with the greatest melasma incidence in the dataset, reinforcing the cofactor model rather than a simple causal one.
HRT and Melasma: The Evidence Gap
The association between hormone replacement therapy and melasma is clinically plausible but, as a 2026 review in Dermatologic Surgery makes clear, poorly supported by prospective data. The existing evidence base consists largely of case reports rather than controlled studies. The authors found that high-dose oral oestrogen-only formulations had the strongest documented association, with cases including forearm melasma in women with Fitzpatrick types III to VI.
Combined oral HRT has case-report evidence. Transdermal formulations have considerably less documented association, a pattern consistent with the oral/systemic route being the primary amplifier of melanocyte stimulation. Vaginal and topical HRT preparations have minimal documented association with new-onset melasma.
The practical implications for aesthetic practice are two. First, a thorough hormonal history must include not only contraceptive use but also HRT, including the formulation, route, and how long the patient has been using it. Women who developed melasma during pregnancy or on combined OCPs are at higher risk of HRT-triggered recurrence, because the melanocyte sensitivity established by those earlier exposures often persists.
Second, practitioners are not the prescribers of HRT, and should not advise patients to stop. What aesthetic practitioners can do is document the correlation, provide appropriate photoprotection counsel, and communicate clearly with the patient's GP or gynaecologist about the skin findings, which may be relevant to formulation decisions. The Dermatologic Surgery review recommends counselling at-risk women on melasma risk before starting HRT, and ensuring strict photoprotection is in place.
Perimenopause and New-Onset Melasma
Perimenopause presents a distinct clinical picture because the trigger is not a consistent high-dose hormonal exposure, but erratic fluctuation. Oestrogen levels during perimenopause oscillate widely before declining, and these fluctuations are sufficient to destabilise melanocyte regulation in women who have never previously had hormonally driven pigmentation.
A 2025 systematic review in the American Journal of Clinical Dermatology examining dermatoses associated with menopause identified melasma among the conditions with documented increased incidence in the perimenopausal period. The authors note that the skin effects of the menopause transition remain underappreciated in both dermatology and aesthetic medicine, and that practitioners treating older women for other concerns may not recognise new pigmentation as perimenopausal in origin.
This matters because the history a practitioner would take for a 28-year-old presenting with OCP-associated melasma and the history appropriate for a 49-year-old presenting with new hyperpigmentation are not the same. In the latter case, the question is not only "are you on any hormonal contraception" but also "have you noticed changes to your cycle, any symptoms consistent with perimenopause, or have you recently started any hormone-containing treatment?"
Perimenopause-associated melasma tends to be more symmetrical, centrofacial, and resistant to topical treatment than post-inflammatory hyperpigmentation, and does not improve with simple UV avoidance the way some seasonal pigmentation does. The underlying hormonal instability means that results from topical treatment are typically slower and more variable than in post-inflammatory or idiopathic melasma, and maintenance is ongoing rather than finite.
Treatment Planning When Hormones Are the Driver
The treatment foundation for hormonal melasma does not change based on the hormonal trigger. Broadband and narrow-spectrum UV protection, tyrosinase inhibitors, and agents targeting the melanocyte-keratinocyte signalling axis are the core tools regardless of whether the driver is an OCP, HRT, or perimenopausal flux.
What does change is the realistic expectation-setting and sequencing.
Active hormonal stimulation makes the skin a moving target. In patients who remain on combined OCPs or HRT, topical treatment is maintenance rather than cure. Where the hormonal trigger can be addressed at source, the trajectory of topical treatment typically improves. Where it cannot, or where a perimenopausal patient has no option that removes the hormonal driver, treatment aims to reduce pigment burden, slow new deposition, and hold the clinical result with maintenance photoprotection.
Chemical peels and resurfacing procedures carry an elevated risk of post-inflammatory hyperpigmentation in melasma patients, and that risk increases in active hormonally driven disease. Sequence carefully: stabilise the pigmentation with topical treatment and photoprotection before considering procedural interventions. Do not attempt aggressive resurfacing in active melasma.
The use of tranexamic acid, whether topical or as part of a practitioner-led protocol, is increasingly supported by the evidence base reviewed in a 2024 meta-analysis covered in the Journal. For hormonal melasma specifically, tranexamic acid's antiangiogenic and anti-keratinocyte-signalling mechanisms address the vascular component that purely tyrosinase-targeting agents do not.
Hyperpigmentation is the presentation Aesthetics Unlocked's clinic sees most weeks. The course framework maps from history-taking through to differential assessment, treatment planning, and trigger management, structured around the NICE-aligned framework the clinic runs.
If you are working through a complex melasma case and want a structured walk-through of pigment assessment and treatment layering, Hyperpigmentation Decoded, The Mini covers the three-lesson introduction at no cost. The free pigment quiz is a useful starting point if you are mapping a patient's pigmentation pattern ahead of consultation.
For the full clinical framework, including treatment sequencing for hormonally driven presentations, Hyperpigmentation Decoded covers the evidence base in detail.
FAQ
Do oral contraceptives always cause melasma? No. Combined OCPs increase melasma risk in susceptible women, particularly with cumulative exposure over three or more years and in conjunction with UV exposure. Skin type, genetic predisposition, and UV habits are cofactors. Not all women on OCPs develop melasma, and risk appears lower with hormonal IUDs than with oral systemic formulations.
Can HRT cause melasma for the first time in a postmenopausal woman? Yes, though the evidence is limited to case reports. High-dose oral oestrogen-only formulations have the strongest documented association. Women who had melasma during pregnancy or on combined OCPs are at higher risk of recurrence on HRT. Transdermal formulations appear to carry lower documented risk, though prospective data remain limited.
Does perimenopause always worsen existing melasma? Not universally, but the fluctuating oestrogen levels characteristic of perimenopause are sufficient to destabilise melanocyte regulation in women with a history of hormonal sensitivity. Some women develop new melasma in perimenopause for the first time. The unpredictable hormonal environment makes this period more treatment-resistant than stable-phase melasma.
Should aesthetic practitioners advise patients to stop their contraceptive or HRT if melasma develops? No. This is a prescribing decision and outside the scope of aesthetic practice. Practitioners can document the correlation, provide photoprotection guidance, and encourage the patient to discuss formulation options with their GP or prescriber. Clear communication between aesthetic and primary care teams benefits the patient.
What is the first-line treatment for hormonal melasma? Broadband UV protection is the non-negotiable first step, regardless of the hormonal driver. Topical treatment typically combines a tyrosinase inhibitor, a retinoid where tolerated, and an agent targeting the keratinocyte-melanocyte signalling axis such as tranexamic acid. Treatment is maintenance rather than cure where the hormonal trigger remains active.