Used by millions of people worldwide, tretinoin is one of the most effective medications on the market for treating and preventing acne.
It’s also safe and well tolerated, with fewer side effects than more powerful oral retinoids such as Accutane (isotretinoin) and significant stronger effects than over-the-counter acne products such as facial scrubs and lotions.
A common question related to tretinoin is whether or not it’s safe to use the medication over the long term. Many would-be tretinoin users are unsure of whether tretinoin is intended as a quick, short-term treatment for acne or a consistent, long-term solution.
For most people, tretinoin is prescribed as a long-term medication for several months or years of consistent, continuous use. In fact, studies show that tretinoin takes two to six months to start to produce noticeable results as an acne treatment.
Studies also show that it’s safe to use tretinoin over the long term, with some studies examining the effects of tretinoin for as long as four years.
In this guide, we’ll look at several studies of short and long-term tretinoin use to help you learn more about how tretinoin works over the long term and how you can best use tretinoin to treat and prevent acne.
In general, it takes three to six months to see results from tretinoin. This is supported by several studies, all of which showed a significant improvement in skin quality and reduction in acne after 12 weeks of using tretinoin.
Unlike many over-the-counter skincare products, which promise immediate results, tretinoin can take several months to start working. It’s also quite common to experience a temporary increase in acne during the first few weeks of using tretinoin.
Most studies show that the acne prevention results from tretinoin improve steadily over the first three to six months of use. For example, in a 1989 study, participants perceived improvement in their facial appearance after six months of treatment.
The researchers also measured objective improvements in fine and coarse facial skin wrinkling, looseness, sallowness and hyperpigmentation in the tretinoin group.
In short, tretinoin isn’t an instant fix for acne. Instead, it works gradually over the course of three to six months to treat existing acne and preventing whiteheads, blackheads and other facial skin lesions from developing in the future.
Tretinoin has been approved as an acne medication since 1962, giving it a track record of more than 50 years. Since it was first marketed in the 1960s, there have been numerous studies into tretinoin’s long-term safety and effectiveness.
While there obviously aren’t any studies covering tretinoin’s entire 50+ year period of availability, several studies show that tretinoin is safe for use over the long term.
In a 2005 study, participants were given either .05% tretinoin cream or a placebo and instructed to use the medication daily. Their results were recorded over a period of two years -- one of the longest studies of tretinoin ever carried out.
Over the course of two years, tretinoin produced a “significantly greater improvement” than the placebo cream in clinical signs of photodamage, ranging from fine and coarse wrinkling to skin hyperpigmentation, sallowness and lentigines (liver spots).
The study concluded that long-term treatment with topical tretinoin cream is “safe and effective in subjects with moderate to severe facial photodamage.”
An even longer study carried out in 1996 evaluated the long-term effects of tretinoin over four years. Study participants with photodamaged skin were instructed to use topical tretinoin daily, with “no untoward effects on keratinocytes or melanocytes” during the long-term study.
Although these studies weren’t focused on the acne prevention benefits of tretinoin (both were aimed at assessing tretinoin as an anti-aging treatment), both studies found that there were no negative effects from long-term tretinoin use over the course of two to four years.
There are also anecdotal cases of people using tretinoin for decades. A New York Times piece on Retin-A, a popular brand of tretinoin cream, featured people who’ve been using tretinoin as an acne prevention and anti-aging treatment for as long as 15 years.
Tretinoin tends to produce noticeable results after three to six months, with the improvements in skin clarity, pigmentation and acne prevention usually continuing as you use the cream, gel or solution over the long term.
Side effects from long-term tretinoin use are rare -- in fact, the vast majority of negative effects from tretinoin tend to occur during the first few weeks of treatment before getting less severe as your skin gets used to the medication.
On the whole, tretinoin is designed as a long-term acne treatment and prevention medication, meaning you’ll likely need to use the medication for several months at minimum. As a topical cream, tretinoin is an easy, convenient medication to take over the long term.
If you’re considering using tretinoin, the best approach is to follow your doctor’s instructions and work with them to assess your progress. Over the course of three, six, 12 or 24 months, you can keep track of your results from tretinoin and assess whether the treatment is worth continuing.
As your skin improves, your doctor might also recommend adjusting your tretinoin dosage over time to provide continual benefits -- an approach that’s been successfully used in some studies of tretinoin as an acne prevention medication.
Interested in using tretinoin to treat and prevent acne? From minor outbreaks to severe, painful cystic acne, tretinoin is highly effective at removing facial acne and preventing it from returning.
Our Complete Guide to Using Tretinoin for Acne covers everything you need to know about how you can use tretinoin for acne treatment and prevention, from choosing the right tretinoin cream or gel to applying topical tretinoin to your skin.
Our guide to tretinoin for cystic acne also covers how tretinoin can be used along with antibiotics to treat outbreaks of inflamed, infected cystic acne.