When shopping for skin care, it feels like we're all searching for the fountain of youth in a bottle. While that doesn't exist (yet), a regular skincare routine can help you make your skin the best it can be. In addition to using a daily sunscreen, cleanser and facial moisturizer, introducing a retinoid into your routine can encourage clearer and healthier skin.

Retinoids have been used since 1971 as a topical treatment for acne and quickly turning over skin cells. These products also boost collagen. Tretinoin was the first retinoid approved by the U.S. Food and Drug Administration, but it's no longer the only retinoid in the game. Retinol is also quite popular, partly because it's available over the counter. Depending on your specific needs and skin type, a medical professional like a dermatologist may recommend one of these products over the other.

What is tretinoin?

Like all retinoids, tretinoin is a synthetic form of vitamin A. This particular medication is primarily used as an acne treatment, though it can be used on patients who want to clear up unwanted skin discoloration, sun spots and fine lines. The tretinoin formula is so strong that it is only available by prescription. The medication works by quickly turning over older skin cells into new cells and keeping skin pores clear. You can get the topical treatment in the following strengths: 0.01%, 0.02%, 0.025%, 0.05%, 0.08% and 0.10%.

Tretinoin benefits

Tretinoin has several benefits. As Dr. John Lowe at Restore Care explains, the medicine can reduce swelling, stop the formation of blackheads, keep pores from clogging, and promote collagen synthesis to remove wrinkles. He says the powerful retinoid may also help get rid of dark spots, noting, "This is particularly helpful for those with hyperpigmented skin lesions resulting from sun exposure and melasma, since it can greatly transform their complexions when used continuously." In other words, you may be able to reduce the visibility of some sun damage.

Tretinoin side effects

You can expect to see some side effects from the use of tretinoin, given its strength. According to a review of scientific trials published in the International Journal of Women's Dermatology, the most common side effects from tretinoin use are dryness, scaling, burning sensation, and erythema (redness). Lowe notes that side effects are often most noticeable in the initial weeks of treatment. This product can also make your skin sensitive to the sun.

Read more: The 12 Best Eye Creams

What is retinol?

Retinol is a less potent retinoid often included in over-the-counter skin care products like serums and lotions. Dr. Steve Gendron of Mindful Living Choice, who has a PhD in physiology-endocrinology, calls retinol tretinoin's "gentler cousin." He points out that because it's less potent, "it works more gradually, giving you results without the intense side effects."

Retinol benefits

A 2015 study in the Journal of Cosmetic Dermatology concluded that "topical application of retinol significantly affects both cellular and molecular properties of the epidermis and dermis." In other words, a topical retinol product can affect both your outermost and middle layers of skin. Like tretinoin, these products can help you reduce wrinkles and discoloration. It will just take longer to see the results.

Retinol side effects

Retinol has similar side effects as tretinoin, but they tend to show up in milder forms when they show up at all. Gendron says many people can expect some irritation, pointing out that "you might experience some dryness and peeling, but it's usually milder than with tretinoin." Because retinol can also make you sensitive to the sun, using sunscreen every day is essential.

Tretinoin and retinol differences

While these two types of retinoids serve a similar purpose, they have two primary differences: how strong they are and how fast they work.

Potency: Tretinoin is stronger than retinol. If you get both products in a strength of 0.05%, the tretinoin will have a more significant effect on your skin.

Speed: Because tretinoin is much stronger, the results appear faster. Doctors may recommend it for people with significant skin issues who are not seeing results fast enough or at all with weaker products.

Who should use tretinoin?

This product is ideal for people with more stubborn skin issues. Lowe says, "People suffering from severe acne, serious signs of photoaging or hyperpigmentation will find tretinoin a good option."

However, you should also consider the potential side effects before you give it a go. The product's strength means you have to take extra care of your face. The doctor warns that patients who ask for this topical agent should be prepared to "commit to strict skin care regimens." He says using soft cleansing agents and moisturizers may help people avoid unnecessary irritation.

The Mayo Clinic warns that people using certain products should discontinue their use when they start tretinoin or reconsider using a strong retinoid. Tretinoin may be too strong for people who use products including:

• Hair removal products
  
• Topical products with a large concentration of alcohol
• Topical products with a peeling agent (including salicylic acid)
• Skin products with spices, lime or other sun-sensitive ingredients

Combining a strong retinoid with the above types of products can lead to an increase in skin irritation or pain.

Who should use retinol?

Retinol is the better product for people who have very sensitive skin because the potency is much lower than that of prescription retinoids. While you may still want to consult a dermatologist or your general physician before using any retinoid, you can start with a low concentration of retinol at home with little risk in most cases.

"The mildness of retinol makes it a preferred choice for sensitive skin. By using retinol, those who have retinoid-sensitive skin can enjoy their benefits without going through the considerable irritation provided by tretinoin," Lowe says.

For people who seek to treat mild signs of aging or imperfect yet acne-free skin, retinol may be the more obvious choice. Gendron agrees, adding, "Retinol wins the sensitive skin contest because it's less likely to cause irritation and redness. It's a gentler option that still offers great benefits without overwhelming delicate skin."

Prescription versus over the counter

Tretinoin is only available with a prescription. A dermatologist, doctor or nurse practitioner with prescriptive authority can write this prescription. The product is gate-kept because of its strength and the need for ongoing supervision.

The good news is that generic tretinoin may be covered by your insurance plan. According to GoodRx, you can get a 45g tube of generic 0.025% tretinoin for as low as $42, though prices will depend on your area and insurance. Nurx advertises the product for just $30 per month. Without any insurance or discounts, the retail price is over $100. However, a single tube can last for many months because you only need a pea-size drop to cover your whole face.

Because retinol products are less potent, you can buy them in any pharmacy or beauty department. Even better, there are a lot of options. You won't be able to get any insurance coverage for over-the-counter options, but retinol products start at about $10.

Key takeaways on retinoids

Retinoids could make your skin appear younger and clear up your skin within just several months. Before you decide which product is right for you, remember:

• Tretinoin is more potent than retinol and requires a prescription. It may not be right for very sensitive skin.
• Retinol is available over the counter but requires patience to see results. It could take several months before you see the payoff.
  
• Both tretinoin and retinol make you more sensitive to the sun. When you use these products, especially tretinoin, you should wear sunscreen every day.
  
• Continue to use other skin care products. Retinoids aren't all-in-one products, so you'll still want to use a gentle cleanser and moisturizer to care for your skin while using tretinoin or retinol.