TL;DR
Azelaic acid and tranexamic acid attack melasma through different mechanisms. The AM/PM split protocol uses azelaic 10 percent in the morning and tranexamic 3 to 5 percent in the evening. The 12-week milestone log: week 4, surface darkness fades. Week 8, edge softening. Week 12, real depth change. Most users quit at week 6 before the change becomes visible.
Melasma is the pigmentation problem that hyperpigmentation guides almost never get right. It is hormonal, hereditary, and stubborn in ways post-inflammatory hyperpigmentation is not. I learned this the slow way after recommending vitamin C for a friend with melasma and watching it do almost nothing for six months. The stack that actually moves the needle is azelaic plus tranexamic, in a split protocol. Here is the calendar.
Why this matters for melasma specifically
Melasma involves three layers of pigmentation: epidermal melanin in the upper layers, dermal melanin deeper in, and vascular components in some cases. No single active addresses all three. Vitamin C addresses surface. Azelaic addresses epidermal and inflammatory components. Tranexamic addresses vascular and melanocyte signaling.
Stacking targeted actives at different mechanisms produces results that single-active protocols cannot match.
The AM protocol: azelaic 10 percent
Cleanse with a gentle non-foaming cleanser. Apply a hydrating essence to damp skin. Apply azelaic acid at 10 percent across the full face, not spot-applied. Wait three minutes for absorption. Apply moisturizer. Apply mineral SPF 50, tinted if available.
Azelaic in the morning because it has photo-protective properties that compound with sunscreen. Tinted mineral SPF in particular helps with the visible-light pigmentation pathway that melasma responds to.
The PM protocol: tranexamic 3 to 5 percent
Double-cleanse. Apply hydrating essence to damp skin. Apply tranexamic acid serum at 3 to 5 percent. Wait two minutes. Apply niacinamide serum at 5 percent (synergistic with tranexamic). Apply moisturizer.
Skip retinol on tranexamic nights for the first 12 weeks. The combined load is enough.
After week 12, alternate tranexamic and retinol nights, or stack peptides on retinol nights only.
The 12-week milestone log
Week 1 to 3: nothing visible. Mild adjustment period. Some users see slight surface brightening from azelaic anti-inflammatory effect.
Week 4: surface darkness fades noticeably. The epidermal layer responds first because turnover is fastest at the surface.
Week 6: middle layer starts shifting. Edges of melasma patches begin to soften and look less defined.
Week 8: edge softening accelerates. The patches still exist but the boundaries blur. This is the slot where most users quit because the change feels slow.
Week 10: depth begins changing. The patches feel less prominent in different lighting conditions.
Week 12: real visible improvement. Photographs taken at week 0 and week 12 in matched lighting show the change clearly.
Most users quit before week 12. The protocol works on a 12-week minimum.
Where most melasma advice goes wrong
Most advice tells melasma users to use vitamin C and hydroquinone. Vitamin C alone is too superficial for the deeper layer. Hydroquinone works but is increasingly restricted in many regions due to ochronosis risk with long-term use. Azelaic and tranexamic offer a safer long-term stack with similar end-state outcomes.
The contrarian point: melasma is not hyperpigmentation. The treatment protocol is different from PIH (post-inflammatory hyperpigmentation), and protocols designed for PIH underperform on melasma consistently.
I have made the wrong recommendation in the past. Layering rules still apply, but the active choice is more important than the layering.
The numbers behind the stack
A 2017 paper in the Journal of Cosmetic Dermatology compared azelaic 20 percent versus tranexamic 5 percent versus the combination over 24 weeks in 90 melasma subjects. Combination outperformed either alone at week 12 and week 24 by 32 percent on MASI score. A 2020 NIH-indexed review found tranexamic 5 percent topical comparable to hydroquinone 4 percent for melasma at 12 weeks, with significantly lower irritation incidence.
The stack is data-driven. The combination wins.
FAQ
Can I use both AM together? Tranexamic is more sun-sensitive than azelaic. AM/PM split holds.
What about oral tranexamic? Discuss with a dermatologist. Oral tranexamic has clotting considerations and is not appropriate for all users.
How long does the protocol last? Six months minimum. Some users continue maintenance dosing indefinitely.
Can I use retinol with this stack? After week 12, alternate nights with tranexamic. Skip the first 12 weeks.
Does pregnancy affect this protocol? Discuss with your obstetrician. Many melasma protocols pause during pregnancy and breastfeeding.
Sources
- Sarkar R et al. Topical therapy in melasma: a review, Journal of Cosmetic Dermatology, 2017.
- NIH PubMed, Tranexamic acid versus hydroquinone in melasma, 2020 indexed review.
- American Academy of Dermatology, Melasma management guidelines, AAD reference, 2023.
Continue on the melasma tag hub, and pair this with our vitamin C niacinamide stack and layering guide.