Glycolic acid has become one of the most celebrated ingredients in skincare, especially in the realm of chemical exfoliation. From clearing acne to smoothing wrinkles, this powerful alpha hydroxy acid (AHA) offers a wide range of benefits. But what exactly is glycolic acid? How does it work, and who should (or shouldn’t) use it? In this comprehensive blog post, we’ll cover everything you need to know about glycolic acid — from its properties and benefits to its side effects and proper usage.
What is Glycolic Acid?
Glycolic acid is a type of alpha hydroxy acid (AHA), a group of natural acids derived primarily from fruits and milk. It is most commonly extracted from sugarcane. Chemically, it is the smallest molecule in the AHA family, which allows it to penetrate the skin deeply and work effectively.
Because of its exfoliating properties, glycolic acid is widely used in skincare products such as cleansers, toners, serums, and peels. Its main function is to help remove dead skin cells from the surface of the skin, promoting a brighter, smoother, and more youthful complexion.
Properties of Glycolic Acid
Below is a table summarizing the key chemical and physical properties of glycolic acid:
| Property | Description |
|---|---|
| Chemical Formula | C₂H₄O₃ |
| Molecular Weight | 76.05 g/mol |
| pH (in solution) | Typically ranges from 2 to 3 (acidic) |
| Molecular Structure | Simplest alpha hydroxy acid (smallest AHA) |
| Solubility | Soluble in water, alcohol, and ether |
| Source | Naturally derived (e.g., sugarcane) |
| Type | Alpha Hydroxy Acid (AHA) |
| Function | Exfoliant, humectant |
| Stability | Sensitive to light and heat |
| Appearance | Colorless, odorless crystalline solid or liquid |
How Does Glycolic Acid Work?
Glycolic acid works primarily as an exfoliant. Unlike physical exfoliants (like scrubs) that mechanically remove dead skin cells, glycolic acid chemically dissolves the “glue” (desmosomes) that hold dead skin cells together on the surface of the skin. This process encourages the shedding of dead cells, revealing fresher, younger skin underneath.
Because it has the smallest molecular size among AHAs, glycolic acid penetrates the skin more deeply than other acids like lactic acid or mandelic acid, making it highly effective.
The exfoliation process triggers a mild inflammatory response that leads to increased collagen production over time. This collagen boost helps improve skin elasticity and reduce the appearance of fine lines and wrinkles.
Additionally, glycolic acid increases cell turnover, which helps fade hyperpigmentation, acne scars, and uneven skin tone. It also improves the absorption of other skincare ingredients, enhancing overall skincare effectiveness.
15 Science Backed Benefits of Glycolic Acid
1) Exfoliates Dead Skin Cells:
Removes the outer layer of dead skin cells to reveal smoother, brighter skin.
2) Improves Skin Texture:
Makes the skin feel softer and look more even by smoothing rough patches.
3) Reduces Fine Lines and Wrinkles:
Boosts collagen production, which plumps up skin and reduces the signs of aging.
4) Fades Hyperpigmentation:
Helps lighten dark spots, sun spots, and melasma by speeding up cell turnover.
5) Treats Acne:
Clears clogged pores by removing dead skin cells and excess oil, reducing breakouts.
6) Minimizes Pores:
Unclogs pores and makes them appear smaller and less noticeable.
7) Improves Skin Hydration:
Acts as a humectant, attracting moisture to the skin and improving hydration.
8) Enhances Skin Radiance:
By clearing away dull dead cells, glycolic acid reveals a natural glow.
9) Prepares Skin for Other Treatments:
Enhances absorption of serums, moisturizers, and other active ingredients.
10) Reduces Acne Scarring:
Promotes regeneration of skin cells, helping to smooth and fade scars.
11) Balances Skin pH:
Helps maintain an optimal acidic pH that protects the skin barrier.
12) Reduces Inflammation:
In low concentrations, can help soothe mild inflammation caused by acne or other skin conditions.
13) Helps With Keratosis Pilaris:
Smooths bumpy skin by exfoliating and softening rough patches.
14) Non-Comedogenic:
Does not clog pores, making it safe for oily and acne-prone skin types.
15) Improves Overall Skin Appearance:
Regular use results in healthier, clearer, and more youthful skin.
10 Side Effects of Glycolic Acid
While glycolic acid is effective, it can also cause side effects, especially if overused or used improperly:
1) Skin Irritation:
Redness, itching, or stinging sensations can occur, particularly with high concentrations.
2) Dryness and Peeling:
Excessive exfoliation may strip the skin of natural oils, leading to dryness and flaking.
3) Increased Sun Sensitivity:
Glycolic acid thins the outer skin layer, making it more vulnerable to UV damage.
4) Burning Sensation:
A mild burning feeling is common but severe burning could indicate overuse.
5) Allergic Reactions:
Rare but possible; symptoms include rash, swelling, or hives.
6) Post-Inflammatory Hyperpigmentation (PIH):
Overuse or improper use can sometimes worsen pigmentation in sensitive skin.
7) Eye Irritation:
Contact with eyes can cause stinging and redness.
8) Worsening of Active Acne:
Sometimes, initial use may cause a “purging” effect where acne temporarily worsens.
9) Sensitivity in Broken or Compromised Skin:
Should be avoided on open wounds or severely irritated skin.
10) Interaction with Other Acids:
Combining glycolic acid with other strong acids (like salicylic acid) or retinoids may increase irritation risk.
How to Use Glycolic Acid?
Using glycolic acid correctly is essential to maximize benefits and minimize side effects:
1) Start Slowly:
Begin with low concentrations (5-10%) and use once or twice a week.
2) Patch Test:
Apply a small amount on your inner arm or behind your ear and wait 24 hours to check for reactions.
3) Cleanse Skin:
Use a gentle cleanser before applying glycolic acid.
4) Apply to Dry Skin:
Make sure your skin is completely dry to reduce irritation risk.
5) Use a Thin Layer:
Apply a thin, even layer of glycolic acid product over your face, avoiding eyes and lips.
6) Follow Instructions:
If using a peel or mask, adhere strictly to the recommended application time.
7) Moisturize:
Follow with a gentle moisturizer to reduce dryness and support the skin barrier.
8) Apply Sunscreen:
Use broad-spectrum SPF 30+ every day, especially when using glycolic acid.
9) Avoid Combining with Other Actives Initially:
Avoid retinoids, vitamin C, or other acids until your skin adjusts.
10) Increase Frequency Gradually:
Once tolerated, you can increase usage to every other day or as directed by your dermatologist.
Precautions and Warnings
- Sun Protection is Crucial: Glycolic acid increases sun sensitivity. Always use sunscreen during the day and avoid excessive sun exposure.
- Avoid Broken or Irritated Skin: Do not apply on cuts, wounds, eczema, or active skin infections.
- Pregnancy and Breastfeeding: Consult a healthcare professional before use.
- Consult a Dermatologist: Before starting glycolic acid, especially if you have sensitive skin, rosacea, or other skin conditions.
- Avoid Mixing with Strong Actives: Combining with retinoids, benzoyl peroxide, or other acids may cause irritation.
- Not for Use on Children: Glycolic acid is not recommended for children or teenagers without professional guidance.
- Discontinue Use if Severe Reactions Occur: Stop immediately if you experience severe burning, swelling, or allergic reactions.
- Storage: Store glycolic acid products in a cool, dark place to maintain stability.
Who Should Use Glycolic Acid?
- Individuals with Dull or Uneven Skin Tone: To brighten and even out skin.
- People with Acne-Prone Skin: To help clear clogged pores and reduce breakouts.
- Those with Signs of Aging: To reduce fine lines, wrinkles, and improve skin texture.
- People with Hyperpigmentation: To fade dark spots and discoloration.
- Individuals with Rough or Bumpy Skin: To smooth skin and reduce keratosis pilaris.
- Anyone Looking for Gentle Chemical Exfoliation: Suitable for many skin types when used properly.
Who Should Not Use Glycolic Acid?
- People with Very Sensitive or Allergic Skin: May experience severe irritation.
- Individuals with Active Skin Conditions: Such as eczema, psoriasis, or severe rosacea.
- Those with Open Wounds or Broken Skin: Can cause stinging and worsen irritation.
- Pregnant or Nursing Women Without Medical Advice: Best to consult healthcare providers.
- People Using Certain Medications: Such as isotretinoin, which increases skin sensitivity.
- Individuals Who Cannot Avoid Sun Exposure: Due to the increased risk of sun damage.
FAQ’s
When to use Glycolic Acid The Ordinary?
The Ordinary Glycolic Acid 7% Toning Solution is best used at night, after cleansing and before applying serums or moisturizers. Avoid using it more than once per day.
How long to wait to apply moisturizer after glycolic acid?
Wait about 1 to 2 minutes after applying glycolic acid to allow it to absorb and begin exfoliating. Then apply your moisturizer to lock in hydration and soothe the skin.
Can I use glycolic acid every day?
Low concentrations may be safe for daily use, but most dermatologists recommend starting 2–3 times a week. Daily use, especially of higher strengths like 7%, may cause irritation or dryness in sensitive skin.
How many times should I use Glycolic Acid The Ordinary?
The Ordinary recommends using the Glycolic Acid 7% Toning Solution no more than once per day, and preferably only 3–4 times per week for most skin types.
What is the best time to use glycolic acid?
Nighttime is ideal because glycolic acid increases sun sensitivity. Using it at night minimizes the risk of sun damage and allows the skin to renew while you sleep.
When should I use glycolic acid for skin—day or night?
Always use glycolic acid at night. If you use it during the day, be sure to apply a broad-spectrum sunscreen with SPF 30 or higher afterward.
What should you not mix with glycolic acid?
Avoid using glycolic acid with:
- Retinol or retinoids (may cause irritation)
- Vitamin C (may lower effectiveness or cause stinging)
- Other AHAs/BHAs (can over-exfoliate)
- Benzoyl peroxide (can be too harsh combined)
- Use these actives on alternate nights or separate by morning/evening routines.
Can I leave glycolic acid on overnight?
Yes, toners or serums containing glycolic acid are meant to be left on overnight. However, if you’re using a high-strength peel or mask, follow the instructions carefully and rinse it off after the recommended time.
Can I use 7% glycolic acid every day?
Using 7% glycolic acid daily may be too strong for some skin types and lead to over-exfoliation. It’s generally safer to use it 2–4 times per week, depending on your skin’s tolerance.
Does glycolic acid lighten skin?
Glycolic acid doesn’t bleach the skin but can help even out skin tone by fading dark spots, acne scars, and pigmentation over time, giving the appearance of brighter skin.
Does glycolic acid remove tan?
Yes, glycolic acid can help remove surface tanning by exfoliating dead, pigmented skin cells, resulting in a clearer and more even complexion.
Which is better, glycolic acid or vitamin C?
Both have different benefits:
- Glycolic acid exfoliates and clears dead skin, improving texture and tone.
- Vitamin C brightens the skin and fights free radicals, preventing aging and pigmentation.
You can use both in your skincare routine—but ideally at different times of day (vitamin C in the morning, glycolic acid at night).
Is glycolic acid safe for sensitive skin?
Glycolic acid can be too harsh for very sensitive or reactive skin. If you have sensitive skin, start with a lower concentration and patch-test before applying it to your entire face.
Can I use glycolic acid with other active ingredients?
Caution is needed when combining glycolic acid with other actives like retinol, vitamin C, or salicylic acid. These combinations can increase irritation. It’s best to use them at different times (e.g., morning and night) or alternate days.
Does glycolic acid cause purging?
Yes, glycolic acid may initially cause purging—temporary breakouts as clogged pores are cleared. This usually resolves within 2–4 weeks.
How long does it take to see results from glycolic acid?
Many users notice brighter skin within a few days, but significant results like reduced acne or improved texture may take 4–6 weeks of consistent use.
Can glycolic acid make my skin darker or cause pigmentation?
If not used properly, glycolic acid can cause irritation, which may lead to post-inflammatory hyperpigmentation, especially in deeper skin tones. Always follow with sunscreen to prevent this.
Is glycolic acid safe to use during pregnancy?
In low concentrations (under 10%), glycolic acid is generally considered safe during pregnancy, but it’s best to consult a healthcare provider before using any active ingredient.
What’s the difference between glycolic acid and salicylic acid?
Glycolic acid is water-soluble and best for surface exfoliation, while salicylic acid is oil-soluble and penetrates deeper into pores, making it more effective for oily and acne-prone skin.
Conclusion
Glycolic acid is a powerful and versatile skincare ingredient with a proven track record of improving skin texture, clarity, and overall health. Its ability to exfoliate deeply and stimulate collagen production makes it a go-to solution for many skin concerns, from acne to aging.
However, like any potent skincare ingredient, it should be used with care and proper precautions. Understanding how glycolic acid works, its benefits, potential side effects, and how to incorporate it safely into your routine is key to getting the best results.
If you’re considering glycolic acid, start slow, use sunscreen diligently, and listen to your skin’s needs. And when in doubt, consulting a dermatologist can help you tailor your skincare regimen safely and effectively.
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