Five Ingredients Your Skin Cannot Live Without…and How to Use Them

Skin Care

According to the article “Skin Innovations” by Jenny Bailly in the December 2007 issue of Allure magazine, five commonly recommended ingredients by leading dermatologists are retinoids/retinol, alpha hydroxy acids (AHAs), antioxidants, sunscreen, and hydroquinone. Below is a user’s guide for each:

RetinA Micro is available by prescription.

1. Retinoids.

The Benefits: Retin-A, a prescription topical treatment containing a derivative of vitamin A, was first used as an acne treatment. However, around 1985, patients reported a decrease in the appearance of wrinkles and smoother skin, in addition to a reduction in acne. The active ingredient in Retin-A, tretinoin (brand name Renova), is the only chemical to date to receive FDA approval for anti-aging and anti-sun damage properties. According to research by Fisher et. al cited by Dr. Leslie Baumann in Cosmetic Dermatology, retinoids are effective in preventing and treating the collagen loss caused by photodamage. UV exposure decreases collagen types I and III with 24 hours, but treatment of the skin with all-trans retinoic acid prevents the loss of these types of collagen synthesis. In addition, Fisher et. al demonstrated that application of tretinoin inhibits the induction of matrix metalloproteinase genes (more here), which are in part responsible for collagen degradation. According to Dr. Ranella Hirsch, president-elect of the American Society of Dermatologic Surgeons in Allure: “We have beautiful, profound data that shows if you use it for 20 yeras, you’re going to look a lot better than someone who doesn’t.”
When to use them (from Allure): At night only, in small quantity (a pea-size amount to make a thin layer on your face) after cleansing; NOT in conjunction with AHAs. Prescription retinoids should be applied after moisturizer. Retinol, on the other hand, is usually contained in a moisturizer.
What to use with: Sunscreen every morning, as retinoids/retinol make your skin more photosensitive (sensitive to the sun).
What not to use with: Alpha hydroxy acids, benzoyl peroxide (an acne treatment that can deactivate retinoids/retinol). Also avoid vigorous exfoliation or waxing.
When to toss: One year after opening.


AHA Soufflé contains 12% glycolic acid (very strong!) $15.75,

2. Alpha hydroxy acids (AHAs)

The Benefits: Alpha hydroxy acids include glycolic acids and lactic acid. As stated in the December 2007 Allure, AHAs were developed in 1974 by scientists eugene Van Scott and Ruey Yu of Temple University as a potential cure for ichthyosis (a rare form of extremely dry skin), and provided, according to Hirsch, “…for the first time, a reliable mechanism for exfoliating without the potential damage of more abrasive modalities, like grainy scrubs or Buf-Pufs.” Further, according to Dr. David E. Bank, author of Beautiful Skin, alpha hydroxy acids cause increase exfoliation of the outer layer of skin, unplog pores, and function as a humectant to hydrate the skin. Bank also mentions that AHAs have further been shown to stimulate collagen and elastin production in the dermis. Dr. Leslie Baumann, author of Cosmetic Dermatology, further adds that AHAs have been reported in improving mottled pigmentation, fine lines, surface roughness, freckles, lentingines, and to treat actinic and seborrehic keratosis. AHAs seem to be an excellent addition to one’s skincare regime, if not already present.
When to use them (from Allure): At night, after cleansing, NOT in conjunction with retinoids/retinol.
What to use with: Sunscreen every morning, as alpha hydroxy acids make your skin more photosensitive (sensitive to the sun).
What not to use with: Retinoids. Also, avoid vigorous exfoliation or waxing.
When to toss: Six months after opening. Over time, alpha hydroxy acids become more potent, and hence more potentially irritating.

Skinceuticals CE Ferulic, $99.95,

3. Antioxidants

The Benefits: The body defends against free radicals (one of four major contributors to skin aging) with antioxidants, which impede or slow the chain reaction. Antioxidants like beta carotene and vitamins C and E “break the chain,” stopping free radicals from ripping electrons off of other molecules, while other antioxidants, like superoxide dismutase, catalase and glutathione peroxidase, slow the free radical chain reaction by stabilizing the unstable, reactive free radicals. As the body does not produce or ingest enough antioxidants to neutralize all of the free radicals, which come from processes that are both endogenous (within the body, such as human metabolism) and exogenous (outside the body, from pollution, smoking, alcohol, and UV radiation, amongst other sources), free radicals accumulate a great deal of damage within the body over time (WebMD). As a result, many experts recommend use of antioxidants and sunscreen to prevent UV-induced free radical damage. According to Sheldon Pinnell, a dermatology professor at Duke University of School of Medicine who created Cellex-C about twenty years ago and later assisted in the creation of Skinceuticals CE Ferulic: “I was interested in how it [topical vitamin C, an antioxidant] could stimulate collagen synthesis. But we found that it was really good for protecting against sunlight.” As many new antioxidants are coming out over time, a rating system called EPF (environmental protection factor) has been proposed to rank antioxidant strength.
When to use them (from Allure): In the morning, after cleansing, before sunscreen. (It also does not hurt to use them at night in conjunction with hydroquinone and EITHER retinoids OR AHAs.)
What to use with: Sunscreen, as antioxidants boost the protective capacity of sunscreen against UV-induced free radical damage.
What not to use with: Take care when your antioxidant is vitamin C. Do not use vitamin C with alpha hydroxy acids (AHAs) — the two acidic ingredients can irritate the skin.
When to toss: Six months after opening. Also, take care not to expose your vitamin C products (those with L-ascorbic acid in particular) to light, heat, and air, which can destabilize the vitamin C.


Neutrogena Ultra Sheer Dry Touch Sunblock SPF 70, $18.49 for two,

4. Sunscreen

The Benefits: UV exposure has been linked to almost every known cause of aging, from free radical release to matrix metalloproteinase formation to DNA damage, and ultimately, to signs of aging that include sunspots, wrinkles, and collagen loss. According to dermatologist Dr. Doris J. Day, a clinical assistant professor of dermatology at New York University in Allure, “Sun exposure is responsible for 95 percent of wrinkles. It is the single most preventable cause of aging.” One caveat: In the pursuit to look eternally young, don’t jeopardize your health by getting too little sun. Most UV radiation activates vitamin D synthesis in the skin, and so avoidance should not be encouraged for anti-aging purposes. Vitamin D is important for promoting calcium absorption, and works in concert with a number of other vitamins, minerals, and hormones to promote bone mineralization. Insufficient levels of vitamin D have been associated with rickets in children and osteomalacia in adults; sufficient levels for infants, children, and adults are listed below. Most dermatologists recommend stimulating synthesis of adequate levels of vitamin D with ten to fifteen minutes of sun exposure at least two times per week to the face, arms, hands, or back without sunscreen, and taking vitamin D supplements, particularly in the winter months in colder areas.
When to use them (from Allure): In the morning, after cleansing. According to Allure, if it contains chemical sunscreens, apply to bare skin. If it contains physical sunscreens, apply over moisturizer. To clarify, chemical sunscreens include Helioplex (a combination of avobenzone and oxybenzone), avobenzone, oxybenzone, PABA, and Mexoryl. Physical sunscreens include zinc oxide and titanium dioxide.
What to use with: Antioxidants underneath. Antioxidants enhance your sun protection!
What not to use with: Nothing, really. One caveat: If you have sensitive skin, avoid scented and chemical sunscreens, which can be irritating.
When to toss: One year after opening. Sunscreen tends to become less effective over time. (I always mark the date I open mine in permanent marker on the bottle).


Tri-Luma is available by prescription. It contains both retinoids and hydroquinone.

5. Hydroquinone

The Benefits: Since 1982, hydroquinone has been FDA-approved for the treatment of freckles, melasma, and general brown patching. Today, hydroquinone is the most commonly used bleaching agent in the United States. Over time, hydroquinone has acquired a much-deserved high reputation in the dermatology community, as it is considered to be very effective in reducing the appearance of dark spots on the skin. Hydroquinone works by inhibiting the activity of tyrosinase, the rate-limiting enzyme of melanin production, and by increasing the cytotoxicity of melanocytes (melanin-producing cells). However, hydroquinone has been banned in some countries, including France and South Africa, for concerns about increased cancer risk and ochronosis (darkening of the skin) with its use. Yet, most experts seem to say that topically applied treatments with hydroquinone are safe, as Dr. David J. Goldberg, a clinical professor of dermatology at the Mount Sinai School of Medicine reports, “Over 100 scientific articles confirm it is a safe topical for humans; no independent studies prove the opposite.” More on hydroquinone and ochronosis is available here.
When to use them (from Allure): At night, on clean, dry skin.
What to use with: Sunscreen during the day, to prevent further hyperpigmentation. At night, use with retinoids or alpha hydroxy acids. Either product will improve penetration of hydroquinone.
What not to use with: Do not use products containing hydroquinone for longer than four months. After four months, take a one-month break.
When to toss: One year after opening.

As a result, retinoids/retinol OR alpha hydroxy acids, antioxidants, sunscreen, and hydroquinone (for dark spots only) should be incorporated into your anti-aging skin care regime. Happy shopping, and here’s to great skin in ’08! 🙂

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  • Nil

    Hey, thank you for your great article,
    I am confused regarding the maintenance regiment of hydroquinone, in most article it’s stated that it should be used for three months and then three months break, what is the safe way?

  • Nicole

    Hey, I have a quick question. I use the Ambi Fade Hydroquinone. However, Ambi Fade states that it has some AHA added to it (looking at the ingredients, lactic acid). Can I still use it with my retinol, or will it decrease the efficacy?

  • Hi Tonia,

    To be honest, I am completely unsure of how your skin would react to combining retinols/AHA with threading as opposed to waxing or some other method. Typically, skin care, as well as hair removal, sensitivity varies greatly depending on your skin type.

    One recommendation for you would be to consult Dr. Neil Schultz, a rewowned Manhattan-based dermatologist, with your question here:

    Another more general recommendation for you would be to read Dr. Leslie Baumann’s The Skin Type Solution, which addresses how your skin may react to retinols/AHAs and become more sensitive, although the book does not mention hair removal topics with retinols/AHAs.

    I hope that this helps you!

  • Tonia


    I currently need to remove hair from my face every 3 to 4 weeks. I am using AHAs in my cleanser and Vit C and would like to use a retinol product.

    Is the concern withh retinols and AHAs only with waxing? Would threading involving no heat be preferrable? Or is it to do with removing the hair from the root?

    I would greatly appreciate your advice?

  • Dear Sunny,

    As a medical student, I am not able to give personalized recommendations to patients (or readers) as of yet.

    However, I HIGHLY recommend Dr. Leslie Baumann’s book, The Skin Type Solution. The questionnaire will tell you which of 16 different skin types is your own, and then customize a skin care regimen for you in the back of the book. It’s a favorite!

    Hope that this helps!

  • Kathryn

    The article says that retinoids and AHAs shouldn’t be used together. If they’re both on the list then how should I combine them into my skincare? I currently use glycolic acid for exfoliation (my skin is sensitive and I can’t use any sort of scrub), but I would like to use retinol for added wrinkle prevention. Should I use one during the day and one during the night?
    Thank you!

  • Hi Amy,

    I like CE Ferulic under a physical sunscreen, reapplied regularly, but that’s just me.

    Good point though! 🙂

  • amy

    I have a question: the allure article says to apply chemical sunscreens directly to skin–not on top of moisturizer. this makes sense to me, as the chemical sunscreens are absorbed into the skin cells (unlike the physical screens which work by blocking UV rays from getting to cells in first place).

    HOWEVER if the best sunscreens are the new chemical ones (w/ mexoryl and helioplex) and if we all agree we should use Ferulic CE under our sunscreen….

    …then we have to make a tough choice: go with ferulic CE and a physical screen like titanium and zinc oxide OR no ferulic and a chemical screen like mexoryl? with the first scenario you’re getting the antioxidant benefits of Feruilic. with the second, you’re getting more complete sunscreen protection. (but how much more complete is it?)

    any ideas, suggestions, thoughts?? i would love to hear others’ opinions.


  • Sunny

    I love your blog. I wanted to ask what you recommend for dry, sensitive skin. Also, I received an AHA face feel at a skincare facility about a week ago. My face became extremely sensitive and bumpy (likes mashed tofu) after the peel. I wanted to know if that was normal and what products to use to reduce the sensitivity and bumpiness.

    Thank you!

  • Sorry, not quite understand, so what should I use as antioxidant in the morning? Some skincare with Vitamin C in the morning before sunscreen?

  • DermQ

    Why the warning against mixing retinoids and AHAs?


    Great blog about skin care.
    thanks for this blog

  • Pam

    I enjoy reading your blogs. This is great information!

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