When I turned 40, I suddenly developed an obsession with skincare products. No more Cetaphil and drugstore moisturizer for me. I purchased shockingly priced herbal oils from a tiny organic farm, exotic masques, and “scientifically proven” potions containing medical-sounding ingredients that I preferred not to know the origins of. I scooped up anything that promised to slow down—hey, even turn back!—the aging process. After dropping a couple of hundred dollars and developing a nasty rash around my eyes, I slunk into my dermatologist’s office. Looking at me like the pitiful dupe I had become, she told me to use Vaseline around my eyes (how glamorous!) and said, “You need Retin-A, it’s the only thing that works. That, and sunscreen.”

Retin-A, the brand name of generic tretinoin, and similar products, are about as close as you can get to a miracle cream. The terminology gets confusing, so stick with me:

“Retinoids” are a broad class of anti-aging products, including retinol, that are derived from Vitamin A. You’ve probably spotted retinol in many cosmetic and skincare items. However, you can you can only get Retin-A by prescription (similar formulas include Renova and Atralin among others). Tazorac, another prescription-strength retinoid, is even more powerful, but can also be more irritating.

All retinoids accelerate the turnover of skin cells and the production of collagen and elastin, proteins that make your skin youthful and elastic, but Retin-A and the like are the big guns. They’re known to smooth fine lines and rough patches and eliminate age spots. They can also be used to clear up blackheads and acne because they keep your pores from getting clogged with dead skin.

To confuse matters even more, the FDA recently cleared Adapalene, a strong but less irritating Retinoid that was originally developed to fight acne, for over-the-counter sales. Some dermatologists, including my own, are recommending it off-label as a more affordable alternative to pricey prescription products.

Other promising formulas such as The Ordinary’s thrillingly cheap, cult line of OTC retinoids are being developed all the time. A rule of thumb for buying non-prescription retinoids is that they should be packaged in a way that prevents exposure to light (the active ingredients are photosensitive) and Vitamin A should be toward the top of the ingredients list.

Discuss the best formula with your dermatologist. You may want to opt for a prescription cream even though they can cost up to $150 a tube. You only need to use a pea-sized amount each day, so the tube should last for at least a few months.

What else should you know? Prescription strength retinoids can cause irritation, especially when you first start using them. You might experience burning, redness, peeling, and itching—pretty much the opposite of the clear smooth skin you were hoping for. In her excellent skincare blog, cosmetic dermatologist, Leslie Baumann, MD, offers the following tips:

For the first two weeks, use only every third night.

Apply to dry skin over your moisturizer.

Once you adjust to the product, use every other night and ultimately, once a day.

Avoid facial scrubs and waxing.

If your skin is very sensitive, some dermatologists also suggest breaking in your skin with a gentler over the counter retinol cream or serum for a few weeks. Retinoids can make your skin more sun sensitive so use at night, and always apply a day cream with SPF—which I’m sure you are doing anyway. Finally, be patient. It can take up to twelve weeks to see results.

Using Retinoids is a long term commitment. Once you stop applying them, you lose the anti-aging benefits. However, compared with buying fancy serums and creams, getting regular facials, or turning to more painful and invasive measures like chemical peels or dermabrasion, they are quite affordable and low maintenance. They don’t come in sexy packaging, smell like rare Himalayan orchids, or contain fairy dust, but they are something nearly every dermatologist recommends.