Beauty 101: How To Combine Active Ingredients + What To Avoid

The term ‘active ingredient’ is a real buzzword in the skincare world, often seen on packaging, and all over social media. It’s often associated with ingredients like vitamin C, retinol, and AHAs and BHAs – powerful ingredients that make real change to your skin. But what often causes confusion is if and how you should combine them; which ones can you use safely (and effectively) at the same time?

The truth is, there are a lot of myths, and honestly, there’s a lot of different opinions on what does work well together and what should be avoided. Ultimately, having a better understanding of how active ingredients interact with each other and your skin will help you create a routine that has the perfect balance of actives, which won’t cause irritation.

To help clarify the dos and don’ts of layering active ingredients, we brought together three world-renowned dermatologists: NY-based dermatologist Dr. Shereene Idriss, celebrity derm Dr. Lancer, and Founder of his eponymous skincare brand Dr. Dennis Gross.

What is an Active Ingredient?

via Giphy

“Active ingredients are what is giving you the benefits of a particular skincare product. [They’re] what is causing changes in your skin cells to achieve a number of benefits,” Dr. Dennis Gross explains. He says these changes include diminishing fine lines and wrinkles, evening out skin tone, improving radiance, and treating acne. Ultimately, an active is powerful enough to change the structure of your skin. Non-active ingredients include those that make up the rest of the product, for example, glycerin and aloe vera will hydrate and soothe the skin, but they won’t make long-lasting changes.

Dr. Shereene adds, “they’re usually the most potent ingredient in the formulation, and intended to help treat an underlying skincare problem.” While Dr. Lancer points out that the quality of the ingredient and it’s concentration constitutes activity, as well as the quality of the formulation the ingredient is in. For example, if vitamin C is included in a tiny amount, it may not be enough to actively change your skin.

Ingredients can still affect your skin, without being considered active. For example, alcohol is used in some products to stabilize formulas, if it’s used in large quantities it could have a drying effect on your skin, however, it’s still not considered an active ingredient, and the same goes for fragrance – fragrance is often added to enhance your experience or mask smelly ingredients. Not all fragrance is bad, but depending on the type used and how sensitive your skin is, it could cause irritation, so it doesn’t mean it should be avoided completely.

The Most Potent Active Ingredients

via Giphy

Retinol: According to Dr. Idriss, retinol is the “holy grail of all actives, but also has the highest risk of irritating your skin!” Hence, why she recommends to, “start low and go slow, meaning opt for the lightest concentration and use one to two nights a week. Once you know you can tolerate, increase the nights you use it until you can tolerate it nightly! Then once you’re done with your tube, graduate to the next strength.” Retinol is an amazing ingredient that can help to diminish the appearance of fine lines and pores, pigmentation and acne scarring, and it will also help smooth skin and even skin tone.

AHAs and BHAs: These are exfoliating ingredients and when used in the right concentration and frequency, will make a big difference to your skin without doing any harm. Dr. Idriss says, “beware of overdoing it, as I have seen many patients over-strip their skin of its natural oils, wreaking havoc on their skin barrier, resulting in inflammation and worsening breakouts.” If using intense exfoliators, like glycolic acid or those with a high concentration – it may sting your skin – Dr. Idriss recommends only using three to four times a week as part of your nighttime routine. However, if you’re using low-concentration formulas, gentler acids, like lactic acid or PHAs, have been using acids in your routine for a long time, or are not using other potent ingredients, you may be fine to use these daily.

Vitamin C: A powerful antioxidant that protects the skin, Dr. Idriss recommends using a vitamin C product every morning combined with sunscreen, “When combined with a UVA sunscreen, a greater photoprotective effect is added given its antioxidative properties helping reverse the damage accrued from free radicals throughout the day.”

Benzoyl Peroxide: This is a topical treatment for acne that can cause dryness. “Beware of Benzoyl Peroxide as it has the ability to oxidize certain ingredients,” says Dr. Idriss. She continues, “I would only use this in the form of a face wash, which I’d apply on my face and let it sit for a few minutes before jumping in the shower. Once you wash it off, let your skin dry then you’re free to apply your other actives. Word of caution: it’s extremely drying, so take it easy when combining it with a retinoid.”

While these are undoubtedly the most potent ingredients, Dr. Idriss explains that, “depending on its concentration, any ingredient can turn out to be ‘very potent,'” which is why it’s important to understand the effect of each ingredient.

SPF: SPF ingredients are also considered actives, like oxybenzone, avobenzone, octisalate, octocrylene, homosalate and octinoxate, and mineral SPFs, zinc oxide and titanium dioxide.

Dr. Gross says to be wary of prescription-based products as they tend to have a higher concentration of actives. Also, don’t assume less is more, as “a product with a single ingredient at a high concentration can actually cause irritation and throw your skin off-balance,” says Dr. Gross – think strong glycolic acids or retinols. Instead, the secret is to combine potent actives with soothing ingredients, for instance, ferulic acid and retinol as the “ferulic acid eliminates any retinol-caused irritation,” explains Dr. Gross.

Low-Risk Ingredients To Incorporate into Your Routine

If you’re wondering which ingredients are (relatively) safe, Dr. Gross recommends any ingredient that exists naturally in the skin like hyaluronic acid, vitamin C and niacinamide (vitamin B3), as they’ll help rebalance the skin. Dr. Idriss also adds that azeliac acid, niacinamide, and mineral sunscreens tend to be in the “low risk” category. Glycerin, squalane, turmeric, chamomile, and aloe are some other popular ingredients that will typically not cause irritation.

How to Layer and Cocktail Active Ingredients

Now we’ve established the typical ingredients you need to treat with care, here are the expert tips for combining active ingredients for the maximum impact:

When in doubt, spread it out: Dr. Idriss cautions, “If you’re unsure how to layer products or if your skin could even tolerate it, spread out the actives over the course of the week. It’s better to be consistently using an active ingredient over time than to use one sporadically expecting a miracle.” Think vitamin C for daytime and an AHA toner in the evening.

Look for multitasking ingredients: Dr. Gross tells us, “My approach is to use ingredients that do different things so the product becomes a multitasker and does multiple things to improve the skin. Look for products that are already formulated with a cocktail of ingredients – don’t try to mix something yourself. Clinical skincare brands do this best!”

The formulation is key: “Even though a product may appear simple, creating the perfect blend to get it to work is not. A baguette and brioche are both loaves of bread, made up of the same ingredients, but formulated very differently to give you two very different outcomes! The same goes for skincare,” says Dr. Idriss.

Timing is everything: “In a given 24-hour period, stick to using only one potent active ingredient, especially when you’re new to your program, to reduce the possibility of a reaction,” says Dr. Lancer. This is especially true if you are only just starting to use the potent actives we have mentioned. If however, you’re already using vitamin C in your daytime routine, slowly introducing retinol or AHA products into your evening routine should be okay – go slow and see how your skin feels. If it tolerates it well, you can increase use to every evening, if you get dryness or sensitivity, take it back a notch.

Combine actives with calming ingredients: Dr. Gross advises, “To avoid irritation, formulate active ingredients with soothing ones.” Look for products that combine actives like retinol or AHAs with skin-soothing hyaluronic acid or ceramides.

Target one skincare concern at a time: Dr. Idriss suggests to, “Focus on your specific skin problems and tackle them one by one in order to really see the change and gain insight into how your skin responds.”

Incorporate active ingredients into your nighttime regimen: “Use active ingredient-containing products in the evening hours before sleep so that they can provide their maximum benefits,” insists Dr. Lancer.

Can You Combine Vitamin C and Retinol?

via Giphy

Retinol and vitamin C are two of the most popular ingredients in skincare. The question is, can they be used together?

Dr. Lancer believes the answer lies in the “quality of each individual active ingredient as poor ingredients in a poorly made final product (including two products such as Vitamin C and Retinol) will cause irritation.” Dr. Idriss agrees, “it boils down to formulation,” which is why it’s SO important to “know your brand, trust its claims and then dip your toes.” Adding, “To have both in your life, use the vitamin C in the AM and the retinol in the PM.”

However, Dr. Gross insists, “you can use both ingredients but they cannot be formulated and appear in the same product. Vitamin C and retinol in a single bottle deactivates or reduces the potency of each other.” Although he does believe in layering different products containing retinol and vitamin C. However, we have used the Kate Somerville +Retinol Vitamin C Moisturizer Super Charged Anti-Aging Moisturizing Cream, $90, and experienced great results, but again, it’s very potent, so we only use it every other night and don’t combine it with any other actives in the same routine.

The Rules for Combining Retinol and AHAs

via Giphy

Another question we’re often asked is can you combine retinol and AHAs? There is an argument that the acidity of AHAs makes the skin pH to acidic, which lowers the efficiency of retinol – well your skin is naturally acidic and retinol isn’t destabilized by acidity. Dr. Gross argues, “These ingredients work together beautifully.” In fact, he states “retinol applied after AHAs is not irritating at all. In fact, they have an additive effect.” A good example of this is Dr. Gross’ Alpha Beta Universal Daily Peel, $88, which he explains “the peel is two steps, so the acids are shut off after two minutes when you apply step two (the neutralizer).”

Dr. Idriss and Dr. Lancer take a different approach. Dr. Shereene says, “I wouldn’t recommend it especially if you’re new to the retinol game as it may increase your risk or irritation and sensitivities.” Dr. Lancer adds that while he would not use them at the same time, “They can be used in the same routine if divided into AHAs in the morning and retinol at night. You can alternate days, for example, AHA every other morning with a retinol at night then BHA on the alternating mornings with a retinol at night.”

The above info is especially true when you’re new to actives. However, if you’ve been using all these active ingredients for a long time, you might find, as Dr. Gross says, that you can combine a gentle AHA toner with a retinol cream without any irritation. For a gentle acid toner, in our experience, the Glow Recipe Watermelon Glow PHA +BHA Pore-Tight Toner, $34, is gentle enough to use with retinols and vitamin C without adverse reaction or sensitivity.

How to Layer Actives With SPF 

via Giphy

Sunscreen should be used daily, always! Dr. Idriss begins by saying, “SPF should always go on last, and be applied 20 to 30 mins before heading out in the sun.”

In terms of what sunscreen to use, Dr. Gross suggests using a physical SPF as “it sits on the skin’s surface and acts as a reflective shield so it won’t negatively impact any other product you are using. It will, however, protect skin from sun damage and results in healthy, younger-looking skin.” Dr. Gross also warns against chemical sunscreens, “due to a recent FDA study that was published showing that chemical sunscreens are absorbed into the bloodstream at alarming rates – way over the level deemed safe by the FDA. One ingredient – oxybenzone – showed an absorption rate 188 times the safe level after one application.”

Key Takeaways:

• Always introduce active ingredients into your routine slowly, especially those which make claims of high percentages.
• Divide and conquer where you can – your skin has a delicate balance and to use too much will only cause damage – so think vitamin C in the morning, a gentle AHA toner or perhaps a BHA serum in the evening followed with soothing and hydrating serums or moisturizers, or swap out the AHAs and alternate with a retinol.
• Ultimately, if you do overdo it, your skin will most definitely let you know in the form of dryness, sensitivity, redness or tightness. When this happens, remove your actives and focus on using nourishing and hydrating ingredients. Check out our guide for fixing dehydrated skin, which also applies well to skin that has been sensitized by too many actives.

For more expert advice, check out the essential skincare rules derms want you to know.

Disclaimer: Every product we review has been independently selected and tested without bias by our editorial team. We never take payment to review products, however, some brands allow affiliate links, so we may earn a commission if you purchase a product by clicking on one of our links.