Sebum and pH Measurement: Quantifying the Oily-Skin Program

1. Sebum: blotting-paper method (T-zone press 30 min, weigh/grade — low cost) or photometric instruments (instant readings). The baseline and tracking tool of oil-control programs (the oily-skin entry).
2. Skin surface pH: healthy skin is slightly acidic (4.5-6.5) — a sentinel for barrier and microbiome. Post-cleansing pH spikes track barrier damage from alkaline over-washing.

• Standard sites: forehead (T-zone proxy) + cheek (U-zone proxy).
• Time window: unwashed morning is most accurate; in-clinic, standardize to “30 minutes after arrival”.
• pH probes: buffer-calibrated; no recent acid use on the measurement zone.

1. Oil-control baselines: before/after a 4-week program — “sebum output down X%” beats “feels less oily”.
2. Cleanser guidance: data-backed advice to switch soap-based cleansers when post-wash pH spikes.
3. Acne workups: sebum quantification + Wood’s-lamp porphyrins + acne grading complete the oily/acne assessment (the acne program).

Do blotting papers make skin oilier?

No — “the more I blot the oilier” is perception (rebound feel after degreasing); sebaceous glands aren’t negatively feedback-regulated by surface sebum. Blotting as a measurement tool is safe.

Does pH tell me about the barrier?

Indirectly: elevated pH flags a damaged acid mantle — read it together with TEWL for a full picture (hydration and TEWL).

• Oily Skin
• Pores
• Wood’s Lamp