Skincare ingredients can be confusing. The Ingredient Library is designed to make things simpler — learn what ingredients Noreen commonly recommends do, what they may support, and how they fit into a thoughtful routine.
Antioxidants are compounds — including Vitamin C, Vitamin E, and green tea extract — that help neutralize free radicals caused by UV exposure, pollution, and everyday environmental stress before that damage builds up in the skin.
Useful for nearly every skin type, especially clients in sun-exposed or urban environments who want to support long-term skin health proactively.
Most effective in the morning routine, applied after cleansing and before moisturizer and sunscreen, since environmental exposure builds throughout the day.
Why pair with sunscreen? Antioxidants help support the skin's natural defenses while sunscreen blocks UV rays directly — together they offer more complete daily protection than either used alone.
Azelaic acid is a naturally occurring acid found in grains like barley, wheat, and rye. In skincare, it's valued for its calming, brightening, and clarifying properties.
A good option for clients with sensitive, acne-prone, or rosacea-prone skin who want a gentler alternative to stronger active ingredients.
Can typically be used morning and evening, applied after cleansing and before moisturizer. Introduce gradually to build tolerance.
Why is it a good starting point? Azelaic acid is generally well tolerated by sensitive and reactive skin, making it a comfortable way to ease into an active-ingredient routine.
Ceramides are naturally occurring lipids that make up a large part of the skin's outer barrier, helping hold skin cells together and keep moisture from escaping.
Especially helpful for clients with dry, sensitive, or barrier-compromised skin, or anyone incorporating stronger actives like retinol or exfoliating acids into their routine.
Can be used morning and evening, typically applied after treatment serums and before or blended into moisturizer to help lock in hydration.
Why pair with active ingredients? Ceramides help support the skin barrier while stronger actives like retinol or AHAs do their work, making the overall routine more comfortable.
Collagen is the most abundant protein in the skin, forming the structural network that gives skin its firmness and shape. Natural collagen production slows gradually with age.
Useful for clients noticing a gradual loss of firmness or elasticity, particularly those in their 30s and beyond as natural production declines.
Collagen-supporting ingredients and treatments — like Vitamin C in the morning or retinol in the evening — are most effective when built into a consistent, ongoing routine rather than used once.
Why does sunscreen matter here? UV exposure is one of the fastest ways to break down existing collagen, so daily SPF is one of the simplest ways to help protect it.
Elastin is a protein that works alongside collagen to give skin its stretch and its ability to spring back into place after movement or expression.
Best suited for clients noticing reduced elasticity or a less resilient look to their skin, especially after years of sun exposure.
Elastin-supporting ingredients, such as peptides and Vitamin C, are typically worked into an existing morning or evening routine rather than used as a standalone step.
Why is sun protection so important? UV exposure is a leading cause of elastin breakdown over time, which is why daily sunscreen is one of the most effective ways to help preserve it.
Free radicals are unstable molecules created by UV exposure, pollution, and everyday environmental stress. Left unchecked, they contribute to oxidative stress that can affect how skin looks and functions over time.
Helpful context for any client wanting to understand why daily antioxidant protection and sunscreen matter for long-term skin health.
Free radical exposure is highest during the day, from sunlight and pollution, which is why antioxidant protection and SPF are most important as part of a morning routine.
What actually protects against them? Antioxidants like Vitamin C help neutralize free radicals, while sunscreen blocks UV rays at the source — pairing the two offers more complete daily protection.
Glycolic acid is an alpha hydroxy acid (AHA) derived from sugar cane. It has the smallest molecular size of the common AHAs, allowing it to exfoliate the skin's surface effectively.
Well suited to clients with normal to oily or more resilient skin who want noticeable exfoliation and a brighter-looking finish.
Most often used in the evening routine after cleansing. Because it increases sun sensitivity, daily sunscreen is essential the following morning.
Why pair with sunscreen? Glycolic acid increases the skin's sensitivity to UV light, so consistent daily sunscreen is essential to protect newly exfoliated skin and maintain results.
Growth factors are naturally occurring proteins that signal skin cells to support the skin's own renewal and repair process. In skincare, they are typically derived from plant or lab-cultured sources.
Clients interested in supporting skin renewal, especially following treatments designed to stimulate the skin's own repair response.
Often included in serums used after in-office treatments, or incorporated into an evening routine to support overnight renewal.
Why are they often used after nano needling? Treatments like nano needling create tiny channels that allow growth-factor serums to be delivered more effectively, supporting the skin's natural renewal process.
Hyaluronic acid is a naturally occurring substance in the skin that can hold significant amounts of water, helping skin look and feel hydrated, plump, and smooth.
Suitable for nearly all skin types, including sensitive and oily skin, since it hydrates without adding heaviness.
Best applied to damp skin morning and evening, before moisturizer, to help draw in and hold hydration.
Why apply it to damp skin? Hyaluronic acid draws moisture from its surroundings, so applying it to damp skin helps it pull in more hydration rather than pulling moisture from deeper skin layers.
Kojic acid is a naturally derived ingredient produced during the fermentation of certain fungi. It's used in skincare to help visibly brighten and even out skin tone.
Useful for clients concerned with hyperpigmentation, sun spots, or uneven tone who want a fermentation-derived brightening option.
Typically applied in the evening as part of a targeted routine. Daily sunscreen helps protect and maintain results, since kojic acid can increase sun sensitivity.
Why is it often paired with antioxidants? Kojic acid can lose effectiveness when exposed to light and air, so it's frequently formulated alongside antioxidants to help preserve its brightening benefits.
Lactic acid is an alpha hydroxy acid (AHA) derived from milk sugars. It has a larger molecular size than glycolic acid, making it a gentler exfoliant with added hydrating benefits.
A good fit for clients with dry or sensitive skin who want gentle exfoliation without excessive irritation.
Commonly used in the evening after cleansing. Introduce gradually, as lower concentrations may be tolerated more frequently.
Why is it also hydrating? Lactic acid acts as a natural humectant, meaning it helps draw moisture into the skin at the same time it exfoliates.
Malic acid is an alpha hydroxy acid found naturally in apples. It's often combined with other AHAs to gently exfoliate and support smoother-looking skin.
Well suited to clients looking for gentle, well-rounded exfoliation, often as part of a multi-acid formula rather than on its own.
Typically included in evening exfoliating treatments or serums. Daily sunscreen helps protect freshly exfoliated skin.
Why is it often blended with other acids? Malic acid is frequently paired with acids like glycolic or lactic acid to round out an exfoliating formula while keeping it gentle on the skin.
Niacinamide is a form of Vitamin B3 used in skincare to help support the skin barrier while calming the look of redness and refining the appearance of pores.
A versatile option for nearly all skin types, including sensitive, oily, and breakout-prone skin.
Can be used morning and evening, applied after cleansing and before moisturizer. Layers well with most other active ingredients.
Why does it layer so well with other actives? Niacinamide is generally gentle and stable, making it one of the easiest ingredients to combine with acids, retinol, or Vitamin C.
Peptides are short chains of amino acids that act as building blocks for proteins like collagen and elastin, signaling skin to support its own structure.
Clients looking to support long-term firmness and texture as part of an anti-aging-focused routine.
Typically applied in the evening after cleansing and before moisturizer, layered underneath richer creams to help lock them in.
Why pair with a moisturizer? Sealing peptides in with a moisturizer helps hold them against the skin, supporting better results over time.
Retinol is a derivative of Vitamin A that supports skin cell turnover, helping skin look smoother, more even, and more refined over time.
Best suited for clients ready to build tolerance gradually. Not recommended during pregnancy or while breastfeeding without physician guidance.
Used in the evening only, applied after cleansing and before moisturizer. Start two to three times a week and build up as tolerated. Daily sunscreen is essential.
Why pair with sunscreen? Retinol increases the skin's sensitivity to the sun, making daily SPF essential to protect skin and help maintain results.
An antioxidant commonly used in skincare to help protect against environmental stress while supporting brighter, more even-looking skin. It's one of Noreen's favorite ingredients to include in a morning routine.
Useful for someone looking to improve radiance, support an even complexion, or add antioxidant protection to a morning routine.
Commonly applied in the morning, after cleansing and before moisturizer and sunscreen.
Why pair with sunscreen? Vitamin C provides antioxidant support while sunscreen helps protect against UV exposure — a useful pairing in a morning routine.
