When it comes to skin health, there’s a lot of misinformation that spreads online and through word of mouth. Unfortunately, many patients fall for fads over facts, but it’s important to make sure you’re taking good care of your skin through tried and tested methods. Here are a few of the most common myths about skincare and skin products, and what you should know about them.

MYTH #1: Skincare products can only work from the outside in.

Some of the best skincare products aren’t really products at all—they’re foods! We are what we eat, and every type of food you put into your body will affect your skin. Switching to a diet that relies heavily on fruits and vegetables can have a notable influence on the appearance of your skin. Foods high in sugar and fat increase the inflammation in your body (and your face), and alcohol and caffeine can dehydrate your skin.

Plus, don’t forget to hydrate regularly: without water, your skin can become dry and flaky, and it needs hydration to remain well lubricated and healthy looking.

MYTH #2: If your makeup has SPF, you don’t need to wear sunscreen.

It’s certainly helpful to use a daily makeup that includes SPF, but it should be just one layer in your multi-layered defense against the harmful effects of sunlight.

Your daily skincare regimen should include the application of a sunscreen that protects against both UVA and UVB rays. Look for products with the labels “multi-spectrum” or “broad spectrum.” And while you should always include a layer of sunscreen under your makeup, you shouldn’t neglect the rest of your body, either! Sunscreen should be worn on every exposed part of your body, even on cloudy days, and it should also be reapplied as specified on the label.

MYTH #3: When you use a new skincare product, you should see immediate results.

You should really start looking for results after about four weeks. The average time needed for complete skin cell turnover is around 28 days, though this number can fluctuate depending on your age and skin type. In other words, you shouldn’t count on seeing results for the first month after you begin a new skincare routine.

MYTH #4: Scrubbing your face with heavy-duty soaps and exfoliating products will help decrease the amount of acne on your face.

We have only the best of intentions when we scrub our faces—we want to keep ourselves clean, and remove the oils that can lead to breakouts and acne. But when we scrub too much, we may be removing some of the helpful oils that protect and lubricate our skin cells, which can cause facial rashes. While some mild exfoliation—maybe two to three times per week, depending on your skin—can be beneficial overall, it’s important to give your skin a chance to recover between treatments.

Instead, try a gentle, non-comedogenic face wash or cleanser, followed by sunscreen in the morning or moisturizer in the evening.

Hopefully, you haven’t fallen for these common skincare myths—but if you have, now is the time to take steps to correct any damage to your skin! And going forward, don’t forget: when in doubt, talk to your dermatologist.