30-Day Skincare Test Timer
Pick one product. Hold the rest of your routine steady. Count the honest 30 days.
Why 30 days?
Skin cell turnover is about 28 days for adults. Most active ingredients need 4 to 6 weeks to show real change. Anything shorter and you are reading noise, not signal.
- BHA / salicylic acid: 4 weeks for texture change
- Niacinamide: 4 to 8 weeks for tone and oil control
- Retinoids (retinol, tretinoin, adapalene): 8 to 12 weeks, with a "purge" in weeks 2-4
- Vitamin C: 4 to 12 weeks for pigmentation
The single-product rule: change one variable, hold the rest steady. If you swap three products at once and your skin improves, you don't know which one helped. Worse, if it gets worse, you don't know which to drop. Pharmaceutical trials use the same logic.
Want the measurement, not just the timer?
This timer counts days. Trace counts the actual breakouts in your daily face scan. Acne, redness, pores, dullness. All measured on your iPhone, nothing uploaded to the cloud.
Get Trace on the App Store →