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Skin science article

Tirtir Pure Vitamin C24 Serum Versus Paula's Choice C15 Super Booster

Tirtir Pure Vitamin C24 Serum Versus Paula's Choice C15 Super Booster This brightening serum is formulated around Ascorbic Acid and Centella Asiatica Extract to brighten dull-looking skin and soften the look of wrinkles. This brightening serum is formulated ar

Tirtir Pure Vitamin C24 Serum Versus Paula's Choice C15 Super Booster

This brightening serum is formulated around Ascorbic Acid and Centella Asiatica Extract to brighten dull-looking skin and soften the look of wrinkles.

This brightening serum is formulated around Ascorbic Acid and Ferulic Acid to brighten dull-looking skin and soften the look of wrinkles.

What's inside

Key Ingredients

Benefits

Concerns

No concerns

Ingredients Side-by-side

Propanediol

Ascorbic Acid

Betaine

Bisabolol

Water

Butylene Glycol

1,2-Hexanediol

Centella Asiatica Root Extract

Centella Asiatica Extract

Centella Asiatica Leaf Extract

Soluble Collagen

Hydrolyzed Collagen

Atelocollagen

Asiatic Acid

Madecassoside

Madecassic Acid

Asiaticoside

Acetyl Hexapeptide-8

Propanediol, Ascorbic Acid, Betaine, Bisabolol, Water, Butylene Glycol, 1,2-Hexanediol, Centella Asiatica Root Extract, Centella Asiatica Extract, Centella Asiatica Leaf Extract, Soluble Collagen, Hydrolyzed Collagen, Atelocollagen, Asiatic Acid, Madecassoside, Madecassic Acid, Asiaticoside, Acetyl Hexapeptide-8

Dipropylene Glycol

Glycerin

Ethoxydiglycol

Sodium Hydroxide

PPG-26-Buteth-26

PEG-40 Hydrogenated Castor Oil

Ferulic Acid

Sodium Phytate

Decylene Glycol

Tocopherol

Sphingomonas Ferment Extract

Phenoxyethanol

Water, Ascorbic Acid, Dipropylene Glycol, Propanediol, Glycerin, Ethoxydiglycol, Sodium Hydroxide, PPG-26-Buteth-26, PEG-40 Hydrogenated Castor Oil, Bisabolol, Ferulic Acid, Sodium Phytate, Decylene Glycol, Tocopherol, 1,2-Hexanediol, Sphingomonas Ferment Extract, Phenoxyethanol

Reviews

Alternatives

Ingredients Explained

These ingredients are found in both products.

Ingredients higher up in an ingredient list are typically present in a larger amount.

1,2-Hexanediol is a synthetic liquid and another multi-functional powerhouse.

It is a:

Humectant, drawing moisture into the skin

Emollient, helping to soften skin

Solvent, dispersing and stabilizing formulas

Preservative booster, enhancing the antimicrobial activity of other preservatives

Ascorbic Acid is is pure Vitamin C and is the biologically active form used directly by skin.

Not only is vitamin C great for your overall health and immune system, but it also has plenty of benefits for your skin. It is best supported by academic literature for:

Topical vitamin C has been shown to help neutralize oxidative stress from UV and pollution, helping to improve photoaging and hyperpigmentation when used consistently.

One clinical study found that using 5% topical vitamin C for six months improved signs of photodamaged skin, both on the surface and in the deeper structural layers of the skin.

While vitamin C doesn’t replace sunscreen, studies show it can boost photoprotection when combined with Vitamin E and ferulic acid. These two ingredients help improve stability and protective effects.

The big downside of this ingredient is formulation difficulty. Vitamin C is prone to oxidation and doesn't penetrate the skin unless formulated correctly. Research found that vitamin C absorbs into the skin best at a low pH (< 3.5) with about 20% being the upper limit for effective absorption.

Skin levels can saturate after repeated application; this means your skin won’t keep absorbing more once it’s full of vitamin C. This is why more isn’t always better with vitamin C and why very high concentrations don’t necessarily give extra benefits.

Ascorbic acid generally works well with many skincare ingredients but can be irritating when combined with other active ingredients. Strong oxidizing acne treatments like benzoyl peroxide can reduce the effectiveness of vitamin C if they are used at the same time; they are often recommended for use at different times of day.

Read more about other types of Vitamin C:

Foods rich with vitamin C include oranges, strawberries, broccoli, bell peppers, and more. When consuming Vitamin C, your skin receives a portion of the nutrients.

Bisabolol is a gentle skin conditioner, antioxidant, and soothing ingredient.

It's primary claim to fame is soothing and research shows topically applied bisabolol can quiet the chemical messengers that cause your skin to become inflamed, helping to sooth any irritation.

A clinical study found that applying 0.5% bisabolol daily for 8 weeks produced an average 9% decrease in skin pigmentation. Researchers found it can also suppress the process that leads to excess melanin production in skin.

In vitro studies found that bisabolol combined with propylene glycol significantly increased skin permeability by increasing lipid fluidity in the stratum corneum.

You'll likely see use concentrations quite low, usually 0.1-0.2%.

Overall, this is a well-tolerated ingredient that works well in formulas designed for sensitive, reactive, or post-procedure skin.

Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin.

It’s often used to:

Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.

Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.

So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.

You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!

Similar Comparisons

The reference edit

Ingredients, questions
& further reading.

Connected source records selected through this article’s public topic index.

01

Formula cabinet

Ingredients & structured notes

Ingredient index

Ingredients Side-by-side

  1. 01Water
  2. 02Panthenol
  3. 03Glycerin
  4. 04Ascorbyl Glucoside
  5. 05Sodium PCA
  6. 06Chondrus Crispus Powder
  7. 07Xanthan Gum
  8. 08Sodium Citrate
  9. 09Sodium Hydroxide
  10. 10Citric Acid
  11. 11Ethylhexylglycerin
  12. 12Phenoxyethanol
  13. 13Water, Panthenol, Glycerin, Ascorbyl Glucoside, Sodium PCA, Chondrus Crispus Powder, Xanthan Gum, Sodium Citrate, Sodium Hydroxide, Citric Acid, Ethylhexylglycerin, Phenoxyethanol
  14. 14Tetrahexyldecyl Ascorbate
  15. 15Dimethicone
  16. 16C9-12 Alkane
  17. 17Silica
  18. 18Pyrus Malus Fruit Extract
  19. 19Hydrogenated Lecithin
  20. 20Polyglyceryl-6 Polyricinoleate
Source · skinsort.com
02

Product index

Related product references

03

Comparison edit

Read side by side