Dear Lisa,
Prior to the development of Retin A in the 1970’s, dermatologists basically relied upon oral Vitamin A to help treat acne, and few topical treatments (if any) helped with signs of photoaging.  Then Retin A, an isomer of the vitamin A molecule, was developed.  Although it was originally used as an acne treatment, Retin-A has numerous applications now, including as an exfoliating agent and “keratolytic” agent (an agemt that removes a plug out of a hair follicle or sweat gland). After that, different delivery systems of tretinoin evolved, including microsponge (with Retin-A Micro) and emollient (with Renova). More recently, synthetic forms of tretinoin, including adapalene (Differin) and tazortene (Tazorac) were invented.  I go into more details about each below:
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(Tretinoin 0.01% Gel; 0.025% Gel; 0.025% Cream; 0.05% Liquid; 0.05% Cream; 0.1% Cream; 0.1% Micro Gel)
Retin-A is indicated for topical application in the treatment of acne vulgaris. Although the exact mechanism of action is unknown, Retin-A seems to act as a keratolytic agent by removing the plug from a clogged pore. It’s still the most widely prescribed retinoid.
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Retin-A Micro

(Tretinoin Gel 0.1%)

Retin-A Micro was approved by the U.S. Food and Drug Administration on February 7, 1997 for the treatment of acne vulgaris. What makes Retin-A Micro unique is the Microsponge® systems technology. The Microsponge® system prevents the accumulation of excessive medication within the surface layers of the skin. It’s pretty neat, actually:  each Microsponge® is less than one-thousandth of an inch in diameter, holding a small amount of tretinoin in reserve and introducing only small amounts of tretinoin to the skin over time. The Microsponge® is believed to be the reason why Retin-A Micro has higher efficacy and lower irritation rates than Retin-A. By contrast, other forms of retinoids may release active ingredients as soon as they are applied, producing a highly-concentrated layer that should absorb into the skin quickly, but which can accumulate in the skin over time. It’s my favorite for acne!


( 0.05% Cream; 0.025% Cream)
Of all the agents listed, only Renova is U.S. FDA-approved for the treatment of skin surface roughness following UV exposure.  Approved by the FDA in 1995, Renova is also clinically-proven to reduce fine facial wrinkles and fade brown spots. Clinical trial data suggests that the emollient system used in Renova is significantly better than Retin-A’s vehicle at minimizing irritancy, the main limiting factor when treating photodamaged skin with retinoids (Biomedical and Life Sciences).  This is because Renova contains an emollient delivery system, meaning that it softens and soothes the skin once it is absorbed. Renova is the best for aging skin, as it increases smoothness and decreases the level of tretinoin-based irritation.
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(Adapalene 0.1% Gel; 0.1% Solution)
Differin (adapalene) and Tazorac (tazarotene) are the two synthetic forms of tretinoin.  Adapalene, a derivative of napthoic acid, possesses similar biological properties of tretinoin, but has higher lipophilicity and increased photostability (i.e., stability in light). Unlike tretinoin, adapalene does not bind to proteins within the cell. Instead, adapalene only binds to specific receptors RAR-β and RAR-γ. Adapalene gel 0.1% has efficacy similar to 0.05% isotretinoin, yet with fewer side effects (British Journal of Dermatology). Its main unique offering is two-fold:

  1. Adapalene may be combined with oral doxycycline (a penicillin) to treat severe acne.  At 12 weeks, the combination has been shown to significantly reduce total, inflammatory, and non-inflammatory acne lesions (SKINmed).
  2. Adapalene is useful in the treatment of melasma, as proven in one study involving Thai patients (Cosmetic Dermatology).


(Tazarotene 0.1% Cream; 0.1% Gel; 0.05% Cream; 0.05% Gel)
Tazarotene is the first retinoid formulated for psoriasis.  It is also indicated for oily skin or severe blackhead form of acne, and still pending review for skin rejuvenation:  “There is limited evidence that tazarotene and isotretinoin benefit patients with moderate photodamage on the face: both are associated with skin irritation and erythema” (Evidence-Based Medicine).
Tazarotene is a prodrug that is metabolized to tazarotenic acid, its active form, within the skin.  Though tazarotene binds to all three retinoid receptors, tazarotene activates gene  RAR-β and RAR-γ.

Bottom Line

Here’s the thing:  All of these are only available by prescription, so if your dermatologist prescribes something other than what I have discussed above, remember to listen to him/her. It’s always best to listen to a licensed physician or aesthetician who is viewing your skin in person, particularly if s/he has seen you in the past!
To summarize:
Retin-A: Most commonly prescribed
Retin-A Micro: Arguably the best for acne
Renova: Best for smoothing skin, arguably the best for aging skin
Differin: Best for severe acne if combined with prescription doxycycline; best for melasma
Tazorac: Best for psoriasis
Looking for the best skin care? FutureDerm is committed to having its customers find — and create — the best skin care for their individual skin type, concern, and based on your ingredient preferences. Learn more by visiting the FutureDerm shop!
Updated 03/25/2015