Is Applying Retin-A Once a Night Too Much for the Skin?

Retin A and other topical retinoids do not "thin" the skin but with long term use over 6 months the skin actually "thickens."   The stratum corneum becomes thinner but the epidermis becomes more acanthotic (thicker).  Most importantly for skin "thickness,"  collagen production can increase resulting in an increased dermal volume.  As always, I recommend consulting a board certified dermatologist so the appropriate skin care regimen can be prescribed and tailored to your specific needs.

I usually advise my patients to start Retin A twice a week at night time and gradually build up to every night.  Retinoids are excellent for epidermal cell renewal and some reversal of sun damage, so regular use is encouranged, however, you don't want to irritate the skin too much by using it every night from the beginning.

Some people with very oily skin may tolerate Retin A nightly from the beginning and may even require a stronger and somewhat more irritating but more effective retinoid, Tazorac

You are right, continuous use of Retin-A will thin your skin. That is why we recommend using Retin-A only in the non-summer months or 9 months out of the year to give your skin a break. Otherwise, Retin-A is excellent for reducing sun damage to the skin.