If there is a single skin care product to choose, I would choose a Tretinoin, which is my favored derivative of Vitamin A or Retinol.  It is prescription strength, so it does require a doctor’s visit (though it is well worth the trip).  Think of Tretinoin as Retinol’s big strong cousin.  The Vitamin A derivatives work by increasing your skin cell turnover, thickening your skin to smooth out wrinkles, and improve skin hyperpigmentation.  Tretinoin does everything that your over the counter Retinol does, but better.  Ask a hundred Dermatologists what the single best thing you can do for your skin is, and they will say “sunblock”.  Ask them what the second best thing is, and you will get “Vitamin A” (or one of its many derivatives).  This post is a part of my Knife Block Approach to Skin Care.

Retinol

Retinols (except for the highest strength) are over the counter, and are popular for this reason.  Major skin care companies tend to favor this because they can sell these over the counter or online without involving a doctor.  They have come up with ways (and a LOT of marketing) to convince people that their “over the counter” products are equivalent to the prescription strength.  Why?  Because prescription products will never have the same ability to be sold at the major department stores!  Instead of the most effective products, they have all focused on giving you the “most effective over the counter” products for their ease of distribution.  All of the major skin care companies (even some “good” ones like ZO Skin and Skin Ceuticals) are guilty of this.
In the past, before the explosion of the cosmeceutical industry, most of these products were distributed at medical offices (mostly by Dermatologists).  The “old” (or “established”, if you will) brands like Obagi made a name for themselves by compromising on nothing and focusing on improving the skin with the best results.  This meant a focus on prescription products with a medically proven track record.  The brand was not as important as effect, as that was the reason for the patient to seek the doctor, and also the reason for the doctor’s recommendation to the patient.
In the changing world that we live in, there has been a huge shift to online sales and direct to consumer advertising, and to adapt to this, companies have done a lot of chemical gymnastics (and much more importantly, marketing) to get the most out of over the counter strengths of products.  The over the counter retinols of today are much stronger and more effective than those of the past.  But why mess around with “over the counter” when there is something that is much more effective?

Tretinoin

Tretinoins come in various strengths, all of which are “prescription strength”.  This means that you can only obtain them with a doctor’s prescription or purchased from an office (or medical spa) that has the ability to sell prescription strength products.  When prescribed for cosmetic use, they are not covered by insurance.    Why do I recommend tretinoin above all else?  You don’t want to skimp on the chef’s knife!  This is the workhorse of your skin care, and is likely not even the most expensive option.  The over the counter “premium” retinols can easily cost more than as twice as much!

Tretinoin Cost

Surely after all of this discussion, the more effective product must cost more, right?  WRONG.
Our workhorse Vitamin A derivative is the Obagi Tretinoin Gel 0.05%, which is a middle strength Tretinoin.  It’s gentle enough to be your first Vitamin A product (after an appropriate break-in period), and it’s also strong enough to be the last Vitamin A that you use.  How much does a 20g tube cost?  Close to $100.  Expensive, right?
Now, look at a “premium” over the counter Retinol, ZO Skin Radical Night Repair.  Another “premium” is the Skin Ceuticals Retinol 1.0, which is a tiny tube that retails for $88.  By my calculations, the “premium” over the counter retinols will cost at least twice as much as the prescription tretinoin once you account for the size of the tube.
This is a product that is the “fountain of youth” of the skin, that you will likely be using for years.  Make sure that you are using a good one that is appropriately strong.  Skimp here (with an expensive over the counter product), and you are not getting the best result per dollar that you spend.  Make the wrong choice, and your wallet will be empty, and you will have a lot of shiny and empty ZO Skin bottles in your trash can.

How to Use Tretinoin

I counsel my patients to start their tretinoin gel at night.  Wash your face with your preferred cleanser, towel dry, and apply a toner (if you use a toner).  Then wait 5-10 minutes to air dry your skin.  Then apply a small amount of tretinoin gel (less than the size of a pea) to your face (skipping the eyelids) and fading down into the neck.
When you are starting out, I recommend this routine:
Use it once a week for two weeks,
Then use it twice a week for two weeks,
Then use it 3 times a week for two weeks,
Then try to slowly increase it to daily use depending on how your skin reacts.
Patients that have ended up with red, irritated, peeling skin have been the ones that jumped into daily use because they wanted results quickly.  Please rest assured that I am not trying to delay your results by ramping up usage very slowly, I just want to make sure you start out in a sustainable way that will not be too much for your skin to handle.
Even after regular use, some people may experience light peeling in some areas (around the mouth and nose), that prevent daily use.  This is ok, and every other nightly use gives great results as well.  Most of my patients love the results enough to accept a little peeling as a small price to pay for the improvement in texture and sun-damaged skin.
All of the Vitamin A derivatives are sun sensitizing, so they must be used with a good sunblock (and remember to reapply!).  They are also not to be used in anyone that is pregnant, lactating, or planning on getting pregnant.