Question 1

Which TCA strength should I start with for a new patient?

Accepted Answer

T2 (TCA 25%) is the standard starter for photoaging and mild melasma. For very superficial work or Fitzpatrick IV+, begin with T1 (15%). Reserve T3–T4 for operators formally trained in medium-depth peeling.

Question 2

Can I use T5–T9 on the full face?

Accepted Answer

No. TCA ≥60% is CROSS-technique (Chemical Reconstruction of Skin Scars) spot treatment only — applied drop-by-drop into the base of individual ice-pick scars or xanthelasma. Full-face application at these concentrations causes scarring (Lee et al., 2002).

Question 3

Do I need HSV prophylaxis?

Accepted Answer

Yes, for any patient with a history of herpes labialis undergoing TCA 25% or higher. Valacyclovir 500mg BID × 7 days starting one day pre-peel is standard of care (Rendon 2010).

Question 4

How does TCA compare to the Jessner–TCA combination?

Accepted Answer

Monheit's Jessner + 35% TCA combination achieves medium-depth results with lower scarring risk than straight 50% TCA. Most modern practitioners use the combination for medium-depth work.

prodermic TCA