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C + AHA

C + AHA

Product Description

Product overview

Made in Various INTERNATIONAL

A powerful two-in-one daytime antioxidant serum combining 15% pure L-ascorbic acid with 10% alpha hydroxy acids (glycolic + lactic acid) to neutralize free radicals, exfoliate dead skin cells, brighten uneven tone, and reduce fine lines and wrinkles. Dermatologist-developed by SkinCeuticals for visible anti-aging and skin-resurfacing results.

15% L-Ascorbic Acid 10% AHA Blend Fragrance-Free Paraben-Free Silicone-Free Alcohol-Free Dye-Free Dermatologist Recommended
Pregnancy
Caution
Fungal Acne
Yes
Comedogenic
1/5
Type
Serum
Size
30 ml / 1 fl oz
Price
~$145
Form
Liquid
Concern
Anti-Aging, Brightening
Real reviews · YouTube Shorts
Why it's different

Dual Antioxidant + Exfoliant

Combines 15% vitamin C for free radical protection with 10% AHAs for surface-level exfoliation — two products in one step.

01

Texture & feel

SENSORY
Consistency
Watery Liquid
Scent
Fragrance-Free
Absorption
30–60 seconds
Finish
Semi-Matte

Dual Antioxidant + Exfoliant

Combines 15% vitamin C for free radical protection with 10% AHAs for surface-level exfoliation — two products in one step.

Enhanced Photoprotection

L-ascorbic acid at 15% provides additional defense against UVA/UVB damage when layered under sunscreen.

Collagen Stimulation

Pure vitamin C is clinically shown to boost collagen synthesis, helping to firm skin and reduce the appearance of fine lines over time.

Surface Renewal

Glycolic and lactic acids dissolve dead skin cells, improving texture, reducing blemishes, and revealing brighter, smoother skin underneath.

02

Safety & compatibility

SAFE
Pregnancy & Breastfeeding

Contains 10% AHAs (glycolic + lactic acid). While topical vitamin C is generally considered safe, high-concentration AHAs may increase skin sensitivity. Consult your OB-GYN or dermatologist before use during pregnancy or nursing.

Fungal Acne (Malassezia) Safe

Contains no fermented ingredients, fatty acids, esters, or polysorbates that feed malassezia. All 12 ingredients are considered fungal acne safe.

Low Comedogenic Risk

Rated 1/5 on the comedogenic scale. Oil-free, silicone-free formula with no known pore-clogging ingredients. Unlikely to cause breakouts.

Sun Sensitivity

AHAs increase photosensitivity. Always follow with a broad-spectrum SPF 30+ sunscreen when using this product. Limit sun exposure.

Sensitive Skin Caution

The combination of 15% ascorbic acid and 10% AHAs at a low pH can cause tingling, stinging, or redness. Build tolerance gradually — start with every other day.

Avoid Combining With

Do not layer with retinol, benzoyl peroxide, or additional AHA/BHA exfoliants in the same routine to prevent over-exfoliation and irritation.

03

Ingredient breakdown

INGREDIENTS

L-Ascorbic Acid (Vitamin C) 15%Proven

The gold-standard form of vitamin C in skincare. A potent water-soluble antioxidant that neutralizes free radicals, boosts collagen production, inhibits melanin synthesis, and enhances photoprotection when paired with sunscreen.

  • Efficacy: Studies show 15% L-ascorbic acid provides optimal antioxidant protection in topical formulations.
  • pH Requirement: Must be formulated below pH 3.5 for effective skin penetration — SkinCeuticals formulates to this standard.
  • Duke Patent: Based on pioneering research by Dr. Sheldon Pinnell at Duke University on topical vitamin C delivery.
L-ascorbic acid is unstable and oxidizes when exposed to light, heat, and air. Product may darken over time — discard if it turns dark brown.

Glycolic Acid Part of 10% AHA blendProven

The smallest alpha hydroxy acid molecule, allowing it to penetrate skin most effectively. Dissolves the bonds between dead skin cells on the surface to reveal smoother, brighter skin and improve texture.

  • Function: Exfoliant that accelerates cell turnover, reduces hyperpigmentation, and smooths fine lines.
  • Molecular Weight: 76 Da — the smallest AHA, offering deepest penetration.
  • Clinical Use: Widely studied for anti-aging, acne, and hyperpigmentation at concentrations of 5–10%.

Lactic Acid Part of 10% AHA blendProven

A gentler AHA derived from milk that exfoliates while also providing humectant properties. Helps brighten skin and improve moisture retention alongside exfoliation.

  • Dual Action: Exfoliates the stratum corneum while drawing moisture into the skin.
  • Molecular Weight: 90 Da — slightly larger than glycolic acid, making it gentler on sensitive skin.
  • Brightening: Inhibits tyrosinase activity, helping to fade dark spots and even skin tone.

Sodium Hyaluronate Not disclosedProven

The sodium salt of hyaluronic acid with a smaller molecular weight, allowing better skin penetration. Attracts and retains moisture, helping to counterbalance the potentially drying effects of the acids in this formula.

  • Hydration: Can hold up to 1,000 times its weight in water, plumping and hydrating skin.
  • Penetration: Smaller molecular size than hyaluronic acid allows deeper delivery into the epidermis.
Helps offset potential dryness from the high-concentration AHA and vitamin C — a smart formulation choice.

Zinc Sulfate Not disclosedPromising

An astringent mineral salt that helps minimize pores, control oil, and soothe skin. Also acts as a stabilizer for the ascorbic acid in the formula.

  • Sebum Control: Helps regulate excess oil production and tighten pore appearance.
  • Anti-inflammatory: Zinc has documented anti-inflammatory and wound-healing properties.

12 ingredients

Aqua / Water / Eau, Ascorbic Acid, Triethanolamine, Glycolic Acid, Propylene Glycol, Glycerin, Citric Acid, Lactic Acid, Phenoxyethanol, Zinc Sulfate, Disodium EDTA, Sodium Hyaluronate

FREE FROM: Parabens, Fragrance, Alcohol, Silicones, Dyes, Oils, Sulfates, Phthalates, Mineral Oil, Formaldehyde, Retinoids, Essential Oils
04

Where it fits in your routine

ROUTINE
1
Cleanser
2
Toner
3
C + AHA Serum
4
Hydrating Serum
5
Moisturizer
6
Sunscreen

Use in the AM only. Apply to clean, dry skin before moisturizer and sunscreen. SkinCeuticals recommends following with Hydrating B5 Gel and a broad-spectrum SPF. Do not combine with retinol or additional exfoliants.

05

How to use

HOW TO USE
1

Cleanse & Dry

Wash your face with a gentle cleanser and pat completely dry. C + AHA should be applied to dry skin for best absorption and to minimize stinging.

2

Dispense 4–5 Drops

Place 4–5 drops of C + AHA into clean, dry palms. A little goes a long way — do not over-apply.

3

Press Into Skin

Gently press the serum into your face, neck, and chest. Avoid the eye area. You may also apply to the backs of your hands for anti-aging benefits.

4

Follow With SPF

Allow 1–2 minutes to absorb, then layer a hydrating serum (optional), moisturizer, and always finish with a broad-spectrum SPF 30+ sunscreen.

06

Who is it for?

WHO

Perfect for you if:

  • You want to combine antioxidant protection and exfoliation in one step
  • You have dull, uneven skin tone or hyperpigmentation
  • You are experiencing early to moderate signs of aging (fine lines, wrinkles)
  • You have normal, combination, or oily skin
  • You want a fragrance-free, clean formula with minimal ingredients
  • You prefer dermatologist-backed, clinically proven formulations

Consider alternatives if:

  • You have very sensitive or reactive skin that cannot tolerate acids
  • You are pregnant or breastfeeding (consult your doctor first)
  • You already use retinol or other strong exfoliants and want to avoid over-exfoliation
  • You are on a budget — at ~$145 for 1 oz, this is a premium investment
  • You need a standalone vitamin C without exfoliating acids
  • You have very dry skin and need richer, more emollient hydration
07

Skin type compatibility

SKIN TYPES
Oily Skin
Excellent

Lightweight watery formula absorbs quickly without adding shine. AHAs help control sebum and minimize pore appearance. An ideal match.

Combination Skin
Excellent

Balances oily T-zone while providing antioxidant benefits to drier areas. Non-greasy, non-heavy formula works well across different zones.

Normal Skin
Excellent

Perfect daily antioxidant treatment. Normal skin can typically tolerate the 15% vitamin C + 10% AHA combination without issues.

Dry Skin
Moderate

The AHA exfoliation benefits dry skin texture, but the formula lacks rich emollients. Must be followed with a hydrating serum and occlusive moisturizer.

Sensitive Skin
Poor

High-concentration acids at low pH may cause significant stinging, redness, and irritation. Start very slowly or consider SkinCeuticals Serum 10 AOX+ instead.

Acne-Prone Skin
Good

Non-comedogenic formula with AHAs that help unclog pores and reduce blemishes. Dermatologist-endorsed for acne-prone skin with signs of aging.

08

Results timeline

MONTH 4–6
Week 1–2

Immediate Glow & Tingling

Noticeable brightening effect and smoother skin texture from day one. Mild tingling or stinging is normal as skin adjusts to the acids. Some users report a subtle "glow" after the first few applications.

70% noticed brighter skin
Week 3–4

Improved Texture & Clarity

Dead skin cell buildup is significantly reduced. Skin feels smoother to the touch, pores appear refined, and overall complexion looks more even and clear.

65% noticed smoother texture
Month 2–3

Dark Spots Fading & Firmness

Hyperpigmentation and sun spots begin to visibly lighten. Collagen-boosting effects of vitamin C start to show with firmer, more resilient skin and softened fine lines.

60% noticed fading dark spots
Month 4–6

Cumulative Anti-Aging Benefits

Consistent use shows significant improvement in wrinkles, skin firmness, and overall radiance. Environmental protection compounds over time for healthier, more youthful-looking skin.

55% noticed reduced fine lines
09

Ratings by platform

580+ REVIEWS
Amazon
4.1
Rating
350+
Reviews
Main complaint: Some bottles arrived already oxidized (dark brown color), likely due to counterfeit or improper storage during shipping
Dermstore
4.3
Rating
100+
Reviews
Main complaint: Expensive for the size — customers feel the cost per ounce is too high compared to CE Ferulic
LovelySkin
4.4
Rating
80+
Reviews
Main complaint: Tingling and stinging on application can be uncomfortable for those with sensitive skin
MakeupAlley
3.8
Rating
50+
Reviews
Main complaint: Sticky texture that doesn't absorb well for some users, and may bleach fabric if not fully absorbed
10

Pros & cons

BALANCED

Praised

  • Two-in-one formula saves a step — antioxidant protection plus exfoliation in one product
  • Noticeable brightening and glow after just a few weeks of consistent use
  • Helps fade hyperpigmentation and dark spots over time
  • Clean, minimal 12-ingredient formula — free from parabens, fragrance, silicones, and dyes
  • Dermatologist recommended and backed by SkinCeuticals' clinical research
  • Fungal acne safe — works for those managing malassezia
  • A little goes a long way — 4–5 drops per application

Criticized

  • Very expensive at ~$145 for just 1 fl oz (30 ml)
  • Can cause significant stinging and tingling on application due to low pH
  • Ascorbic acid oxidizes quickly — 6-month shelf life once opened
  • May bleach fabrics and pillowcases if product transfers
  • Not suitable for sensitive skin without gradual buildup
  • Dropper bottle packaging exposes product to air, accelerating degradation
  • Counterfeits common on third-party marketplaces like Amazon
11

Budget-friendly alternatives (dupes)

DUPES
82% Match
20% Vitamin C + E + Ferulic Acid Serum
$26.95
Budget Pick

Higher vitamin C concentration (20% vs 15%) with added vitamin E and ferulic acid for stability. However, lacks the AHA exfoliation component — you would need a separate AHA product. Extremely popular dupe in the vitamin C space.

72% Match
C15 Super Booster
$52.00
Similar Tier

Same 15% L-ascorbic acid concentration with vitamin E and ferulic acid. Does not include AHAs, so you miss the exfoliation benefit. More stable packaging with an opaque bottle. Trusted brand with strong clinical reputation.

68% Match
Vitamin C Suspension 23% + HA Spheres 2%
$6.80
Budget Pick

Much higher vitamin C percentage in a silicone-based (anhydrous) suspension — completely different texture. No AHAs included. Very gritty feel that many users dislike, but exceptional value. Not a true formula match but delivers potent vitamin C at a fraction of the cost.

12

Comparison with competitors

SIDE-BY-SIDE

SkinCeuticals C E Ferulic

Vitamin C 15% L-Ascorbic Acid
Exfoliant None
Size 30 ml
Ingredients 13
Fragrance None
Fungal Acne Safe Yes
Price/ml $6.07/ml
C-Firma Fresh Day Serum
Vitamin C 15% L-Ascorbic Acid
Exfoliant Fruit Enzymes (mild)
Size 28 ml
Ingredients 20+
Fragrance None
Fungal Acne Safe No
Price/ml $2.79/ml
20% Vitamin C + E Ferulic Acid Serum
Vitamin C 20% L-Ascorbic Acid
Exfoliant None
Size 30 ml
Ingredients 11
Fragrance None
Fungal Acne Safe Yes
Price/ml $0.90/ml
13

Storage & shelf life

6 MONTHS
Period After Opening (PAO)

6 months after opening. L-ascorbic acid is highly unstable and will oxidize over time. Discard if the serum turns dark brown or develops an off smell.

Storage

Store in a cool, dark place away from direct sunlight and heat. Refrigeration is recommended to extend potency and slow oxidation. Keep cap tightly closed after each use.

Packaging

Glass dropper bottle. While professional-grade, the dropper introduces air with each use — consider transferring to an airless pump or minimizing open time.

Travel Friendly

Yes — 30 ml (1 fl oz) is well under the 100 ml TSA carry-on limit. Glass bottle, so handle with care during travel.

13

Frequently asked questions

FAQ

Use with caution. While topical vitamin C (L-ascorbic acid) is generally considered safe during pregnancy, the 10% AHA blend (glycolic and lactic acid) raises concern. High-concentration AHAs can increase skin sensitivity and absorption of other substances. Most dermatologists recommend avoiding AHAs above 5–8% during pregnancy. Consult your OB-GYN or dermatologist before incorporating this product into your pregnancy or breastfeeding skincare routine.

Yes. SkinCeuticals C + AHA is fungal acne safe. The formula contains only 12 ingredients, none of which are known malassezia triggers. There are no fermented ingredients, fatty acids (C11–C24), esters, polysorbates, or oils in the formula. It is a clean, water-based formulation that should not aggravate fungal acne conditions.

This product already contains both vitamin C (15%) and AHAs (10%), so you should not layer additional vitamin C or AHA/BHA products in the same routine. Do not combine with retinol in the same application — use retinol in your PM routine and C + AHA in the AM. If you use other exfoliants like BHA (salicylic acid), alternate days or use them at different times of day to avoid over-exfoliating and compromising your skin barrier.

C + AHA is ideal for normal, combination, and oily skin types. Its lightweight liquid texture absorbs quickly without leaving residue or shine. Oily and combination skin benefit most from the AHA exfoliation and vitamin C brightening. Dry skin types can use it but should follow with a rich moisturizer. Those with sensitive or very reactive skin should approach with caution and start with every-other-day application.

Many users notice an immediate brightening effect and smoother texture within the first 1–2 weeks. More significant improvements in hyperpigmentation, dark spots, and fine lines typically emerge around 6–8 weeks of consistent daily use. Full collagen-boosting and anti-aging benefits develop over 3–6 months. Antioxidant protection is immediate with each application.

Apply C + AHA in the morning as step 3 in your routine: after cleansing and toning, but before hydrating serums, moisturizer, and sunscreen. Apply to clean, dry skin — moisture can dilute the acids and affect absorption. SkinCeuticals recommends following with Hydrating B5 Gel and then a broad-spectrum SPF. This is an AM-only product.

No. SkinCeuticals C + AHA has a comedogenic rating of 1/5, meaning it has a very low likelihood of clogging pores. The formula is oil-free, silicone-free, and contains no known comedogenic ingredients. In fact, the glycolic and lactic acids in the formula actively help unclog pores by dissolving dead skin cell buildup. This makes it a good choice for acne-prone skin.

SkinCeuticals C + AHA should be used within 6 months of opening. L-ascorbic acid is highly unstable and oxidizes when exposed to air, light, and heat. The serum starts clear to light yellow — if it darkens to a deep orange or brown, it has oxidized and lost potency. Store in a cool, dark place (refrigeration recommended) and always close the cap tightly to maximize its shelf life.

— Skincarisma verdict
4.2 / 5 ★★★★☆

Verdict: SkinCeuticals C + AHA is a well-formulated, clinically backed two-in-one serum that delivers potent antioxidant protection and effective exfoliation in a single step. The 15% L-ascorbic acid combined with 10% AHAs is a powerful pairing for tackling dullness, uneven tone, hyperpigmentation, and early signs of aging. Its minimal 12-ingredient, fragrance-free formula is a standout for ingredient-conscious consumers and those with fungal acne concerns. However, the steep ~$145 price tag for just 1 oz, short 6-month shelf life, and potential for irritation on sensitive skin are notable drawbacks. If you have normal to oily skin, can tolerate active acids, and value a streamlined routine with clinical-grade ingredients, C + AHA is an excellent daily treatment. Budget-conscious shoppers may find comparable vitamin C serums for far less, though they'll likely need a separate AHA product to replicate the full dual-action benefit.

Product Overview

question
lightbulb What are Quick Product Notes?

Quick product notes are a great way to check if a product is free from commonly avoided ingredients by skincare enthusiasts. These preferences come about for different reasons depending on the ingredient such as personal experiences, sensitivities, health preferences & etc.

muscle Pro Tip Alert!

Just because a product is not free from a common preference does not mean it's a bad product! You can make a personal decision whether or not you want to use a product that contains these ingredients or not - click the labels of the preference to read more about them.

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Quick Product Notes

Click on icons for more information
question
lightbulb What are Notable Effects & Ingredients?

Ever used a product that promised a certain effect but provided no results? It might not have contained any notable ingredients that could have been responsible for that promised effect. It doesn't matter what the marketing or packaging «promises» it can do, if it doesn't contain anything that can help - then the likelihood of it helping is low.

We help you identify key notable ingredients that have been shown to help with effects such as acne-fighting, brightening, UV-protection, wound healing & anti-aging to help you achieve your skincare goals smarter. Please note that different notable ingredients have varying levels of research behind them, some are extremely well proven yet some have mixed research in their efficacy.

muscle Pro Tip Alert!

Just because a product doesn't contain any notable ingredients doesn't mean it's bad. And a product with notable ingredients (or even many) doesn't necessarily guarantee the efficacy of the product performing these effects either. There are other factors such as ingredient quality, concentration and formulation that will ultimately determine this.

Be smart and use this as just a starting point for you to make more informed and smarter choices and compare it with reviews to see if the product is right for you

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Notable Effects & Ingredients

anti-aging Anti-Aging from 4 ingredient(s):
Ascorbic Acid Glycolic Acid Citric Acid Lactic Acid
brightening Brightening from 5 ingredient(s):
Ascorbic Acid Glycolic Acid Glycerin Citric Acid Lactic Acid
wound Promotes Wound Healing from 5 ingredient(s):
Ascorbic Acid Glycolic Acid Glycerin Citric Acid Sodium Hyaluronate
ache Ache-fighting from 1 ingredient(s):
Glycolic Acid
question
lightbulb What are Ingredients Related to Skin Type?

Why are some products great for some people and horrible for others? Well everyone has different skin types and different reactions to the same ingredients.

We've identified a range of ingredients that are commonly regarded as potentially good or bad for those with Dry, Oily/Acne-Prone or Sensitive skin.

muscle Pro Tip Alert!

A product that contains good or bad ingredients for your skin type doesn't always flat out make the entire product good or bad for your skin. There are other factors such as ingredient quality, concentration and formulation that will ultimately determine your skins reaction.

One of the best ways to use this section is to troubleshoot products you've had bad experiences with in the past. Check if it contains any of the marked ingredients to point out suspect ingredients to avoid in the future!

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Ingredients Related to Skin Types

Click on icons for more information
dry-skin Dry Skin
3 1
oily-skin Oily/Acne-Prone Skin
1 1
sensitive-skin Sensitive Skin
question
lightbulb What is the Ingredient Safety Breakdown?

Ingredient Safety Breakdown refers to the percentage % of ingredients in different risk categories as classified by EWG (Environment Working Group) if they are available. There are almost endless cosmetic ingredients and they are one of the few organisations globally that have assigned ratings to a lot of the more commonly used ingredients which is why we reference them.

muscle Pro Tip Alert!

EWG is seen by many to be more on the alarmist side in their assignment of health ratings resulting in rating ingredients as riskier than they actually are. We recommend using this a reference point rather than a strict guide of ingredient safety and to always do further research if into ingredients that you may find suspect.

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Ingredient Safety Breakdown

EWG Health Ratings
Low risk
Medium risk
High risk
Unknown risk
50% 33% 16%

Product ingredient list

Showing first 5 of 12 ingredients
EWG CIR Ingredient Name & Cosmetic Functions Notes
1 Unknown
Water
Solvent, Skin Conditioning
1 A
Ascorbic Acid
Skin Conditioning, Masking, Fragrance, Antioxidant, Ph Adjuster, Buffering Agent, Buffering
brightening Brightening
anti-aging Anti-Aging
Promotes Wound Healing
Redness
Dark Spots
Texture
Pores
5 B
Triethanolamine
Masking, Surfactant, Fragrance, Emulsifying, Ph Adjuster, Buffering Agent, Buffering
4 B
Glycolic Acid
Ph Adjuster, Buffering Agent, Exfoliant, Exfoliating, Buffering
brightening Brightening
ache Ache-fighting
anti-aging Anti-Aging
Promotes Wound Healing
Dark Spots
Texture
Pores
3 B
Propylene Glycol
Solvent, Skin Conditioning, Fragrance, Humectant, Viscosity Controlling, Viscosity Decreasing Agent, Skin-Conditioningagent - Miscellaneous
Hydrating
VIEW ALL INGREDIENTS