The only FDA approved capsaicin product for PN is Qutenza in which the active ingredient is embedded in a complex delivery system that is applied by a physician every 3 months via a patch. It has virtually no adverse systemic effects but causes local irritation in about a third of the recipients; in controlled trials this irritation , which is generally transient, caused only 1 % to discontinue its use. Vastly lower doses contained in other non FDA approved topicals frequently cause far more inflammation and have low use compliance because of this.