Four weeks of consistent effort and your pigment looks exactly the same. Maybe even slightly worse in certain lighting. That feeling of "this is not working" is completely understandable, and it is almost certainly wrong.
Four weeks is not enough time to assess whether a hyperpigmentation approach is working. For most pigment types, it is not even close. And the impulse to switch products, add more actives, or escalate at this point is one of the most common reasons people derail their own progress.
Why four weeks is too early
Your skin turns over on roughly a 28-day cycle, and that is for younger skin with healthy turnover. As you age, that cycle stretches to 40 days or longer. What that means in practical terms is that the pigmented cells sitting on the surface of your skin right now were produced weeks ago. Even if your treatment started working on day one, the already-pigmented cells need to complete their journey to the surface and shed before you can see the difference.
For surface-level PIH, the earliest you might notice a subtle shift is four to six weeks. For sun spots, closer to two to three months. For melasma, three months is the minimum assessment window. At the four-week mark, you are looking at skin that has not yet had time to reflect what your treatment is doing.
What is actually happening beneath the surface
Even though nothing looks different in the mirror, your skin is not static. If your approach is well-matched to your pigment type and your triggers are under control, the processes driving fading are already underway.
Tyrosinase inhibitors are reducing the amount of melanin being packed into new cells. Cell turnover ingredients are accelerating the replacement cycle. Sun protection is preventing UV from reactivating melanocytes and depositing new pigment. Internal support is helping regulate the inflammatory signalling that tells melanocytes how much pigment to produce.
All of this is happening at the production level. It has not reached the surface yet. That is not failure. That is just how the biology works.
The only red flags at four weeks
There are exactly three things that would be worth paying attention to at this stage. Everything else is too early to call.
New pigment forming in areas that were previously clear. If your approach is causing new marks to appear, something is irritating your skin and triggering fresh pigment production. This warrants a pause and reassessment, not an escalation.
Increased irritation. Stinging, burning, persistent redness, or visible dryness and flaking that is not resolving. This suggests your barrier is being compromised, which will slow fading and can actively make pigment worse. Pulling back on actives and focusing on barrier repair is the right move.
Skin barrier visibly compromised. Tight, shiny skin. Increased sensitivity to products that previously felt fine. Texture changes. If your skin looks and feels worse overall, the intensity of your approach needs to come down, not up.
If none of those three things are present, the answer at four weeks is almost always: keep going.
What to do right now
Take comparison photos if you have not already. Same lighting, same angle, same time of day. Your brain cannot track gradual change. Photos can.
Check your sun protection. If you are not wearing broad-spectrum SPF daily and reapplying during sun exposure, that alone can explain why pigment is not shifting. UV and heat reactivate melanocytes and undo the work your treatment is doing.
Resist the urge to add more. The four-week itch to layer on another serum or try a stronger active is real. It is also counterproductive. More products on skin that is already being treated increases irritation risk, which increases inflammation, which increases pigment. Stay the course.
Give yourself a real assessment window. Eight weeks minimum for surface PIH. Twelve weeks for most other types. Three months before drawing any conclusions about melasma. Mark it on your calendar and commit to not changing your approach before then.
Four weeks is the beginning of a turnover cycle, not the end of a treatment window. If nothing has gone wrong, the most strategic thing you can do right now is nothing different.
