Skin science article
Tula Skincare Wrinkle Treatment Drops Retinol Alternative Serum Versus Paula's Choice Discoloration Repair Serum
Tula Skincare Wrinkle Treatment Drops Retinol Alternative Serum Versus Paula's Choice Discoloration Repair Serum This anti-aging serum is formulated around Bakuchiol and Lactic Acid to soften the look of wrinkles and refine skin texture. This brightening serum
Tula Skincare Wrinkle Treatment Drops Retinol Alternative Serum Versus Paula's Choice Discoloration Repair Serum
This anti-aging serum is formulated around Bakuchiol and Lactic Acid to soften the look of wrinkles and refine skin texture.
This brightening serum is formulated around Niacinamide and Tranexamic Acid to fade the look of dark spots and brighten dull-looking skin.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Diisopropyl Adipate
Dicaprylyl Carbonate
Glycerin
Squalane
Caprylic/Capric Triglyceride
Polyglyceryl-2 Dipolyhydroxystearate
Isoamyl Laurate
Lactococcus Ferment Lysate
Simmondsia Chinensis Seed Oil
Triethylhexanoin
Stearalkonium Hectorite
Bakuchiol
Stevia Rebaudiana Leaf/Stem Extract
Lycium Barbarum Fruit Extract
Daucus Carota Sativa Root Extract
Beta-Carotene
Lactic Acid
Gluconolactone
Lactobacillus
Polyglyceryl-3 Diisostearate
Polyglyceryl-3 Polyricinoleate
Magnesium Sulfate
Squalene
Tocopheryl Acetate
Tocopherol
Alpha-Glucan Oligosaccharide
Propanediol
Lecithin
Polymnia Sonchifolia Root Juice
Sodium Phytate
Medicago Sativa Extract
Hydrogenated Phosphatidylcholine
Lysolecithin
Maltodextrin
Glycine Soja Oil
Calcium Gluconate
Sodium Benzoate
Ethylhexylglycerin
Caprylyl Glycol
Sodium Chloride
Citric Acid
Beta-Sitosterol
Phenoxyethanol
Potassium Sorbate
Phytic Acid
Water, Diisopropyl Adipate, Dicaprylyl Carbonate, Glycerin, Squalane, Caprylic/Capric Triglyceride, Polyglyceryl-2 Dipolyhydroxystearate, Isoamyl Laurate, Lactococcus Ferment Lysate, Simmondsia Chinensis Seed Oil, Triethylhexanoin, Stearalkonium Hectorite, Bakuchiol, Stevia Rebaudiana Leaf/Stem Extract, Lycium Barbarum Fruit Extract, Daucus Carota Sativa Root Extract, Beta-Carotene, Lactic Acid, Gluconolactone, Lactobacillus, Polyglyceryl-3 Diisostearate, Polyglyceryl-3 Polyricinoleate, Magnesium Sulfate, Squalene, Tocopheryl Acetate, Tocopherol, Alpha-Glucan Oligosaccharide, Propanediol, Lecithin, Polymnia Sonchifolia Root Juice, Sodium Phytate, Medicago Sativa Extract, Hydrogenated Phosphatidylcholine, Lysolecithin, Maltodextrin, Glycine Soja Oil, Calcium Gluconate, Sodium Benzoate, Ethylhexylglycerin, Caprylyl Glycol, Sodium Chloride, Citric Acid, Beta-Sitosterol, Phenoxyethanol, Potassium Sorbate, Phytic Acid
Niacinamide
Tranexamic Acid
C13-15 Alkane
Ethyl Macadamiate
Behenyl Alcohol
Glyceryl Stearate
Butylene Glycol
Silybum Marianum Seed Oil
Lactobacillus/Coconut Fruit Juice Ferment Filtrate
Xanthan Gum
Hydrogenated Lecithin
Allantoin
Hexylene Glycol
Boerhavia Diffusa Root Extract
Glycine Soja Sterols
Malic Acid
Water, Niacinamide, Glycerin, Tranexamic Acid, C13-15 Alkane, Caprylic/Capric Triglyceride, Dicaprylyl Carbonate, Ethyl Macadamiate, Behenyl Alcohol, Glyceryl Stearate, Butylene Glycol, Silybum Marianum Seed Oil, Tocopherol, Lactobacillus/Coconut Fruit Juice Ferment Filtrate, Lecithin, Bakuchiol, Xanthan Gum, Caprylyl Glycol, Hydrogenated Lecithin, Allantoin, Glycine Soja Oil, Hexylene Glycol, Boerhavia Diffusa Root Extract, Glycine Soja Sterols, Citric Acid, Sodium Phytate, Malic Acid, Phenoxyethanol, Ethylhexylglycerin
Reviews
Be the first to review
Alternatives
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Bakuchiol is a plant-derived antioxidant from the seeds of the Psoralea corylifolia plant. It has antimicrobial, emollient, skin conditioning, and antioxidant properties.
You'll likely see it called a "retinol replacement" but the two are technically not related. This is because bakuchiol is able to flip many of the same switches in your skin cells to tell them to:
1) produce more collagen (type I, III, and IV) 2) activate the same genes retinoids do
Unlike retinoids, this ingredient will not increase photosensitivity and is safe to use during pregnancy (but please still check in with your doctor!).
The flagship clinical trial from Dhaliwal et al. 2019 found 0.5% bakuchiol (twice daily) and 0.5% retinol (once daily) reduced wrinkles and hyperpigmentation equally, but bakuchiol had significantly less irritation.
Systematic reviews also back this up:
Bakuchiol is comparable to retinol for photoaging but with better tolerability. It also has mild antibacterial properties against Cutibacterium acnes and antifungal activity in vitro against Candida and dermatophytes.
The reason bakuchiol works well is due to its structure; it is a meroterpene phenol, or a hybrid molecule. The phenol half acts as an antioxidant while the terpene half is fat-loving. This helps the molecule slip through the skin barrier.
This ingredient is usually used between 0.5-2%. Only one case of contact dermatitis has ever been reported for this ingredient.
Caprylic/Capric Triglyceride (aka MCT Oil) is a lightweight emollient, solvent, and texture enhancer. It is considered a skin-softener by helping to prevent moisture loss.
Though it behaves like an oil, it is not technically one due to its chemical composition. One perk of this ingredient is that it is very stable, resistant to oxidation, and unlikely to go rancid.
In practice, that translates to a long shelf life and a consistently elegant skin feel.
While there is an assumption Caprylic Triglyceride can clog pores due to it being derived from coconut oil, there is no research supporting this. Just patch test if you have concerns.
Fractionated coconut oil and MCT Oil are both listed as Caprylic/Capric Triglyceride according to INCI. This is because INCI names are based on the ingredient’s final chemical composition and not its marketing name or source.
This ingredient is treated as the gold standard fungal acne safe oil. Even though it is coconut derived, the problematic lauric acid is stripped out.
This leaves just caprylic (C8) and capric (C10) acid. These chain lengths actually trend antifungal; a 2020 study found caprylic acid was enough to disrupt Malassezia furfur cell membrane, with a caprylic acid derivative damaging membrane structures at concentrations as low as 0.2%.
Caprylyl Glycol is a humectant, skin conditioner, emollient, and preservative booster derived from either caprylic acid or synthetically created.
Typical use levels vary from 0.3-1% as a preservative booster and go up to 2% to condition skin.
Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).
Citric Acid is an alpha hydroxy acid (AHA) naturally found in citrus fruits like oranges, lemons, and limes.
Like other AHAs, citric acid can exfoliate skin by breaking down the bonds that hold dead skin cells together. This helps reveal smoother and brighter skin underneath.
However, this exfoliating effect only happens at high concentrations (20%) which can be hard to find in cosmetic products.
Due to this, citric acid is usually included in small amounts as a pH adjuster. This helps keep products slightly more acidic and compatible with skin's natural pH.
In skincare formulas, citric acid can:
While it can provide some skin benefits, research shows lactic acid and glycolic acid are generally more effective and less irritating exfoliants.
Most citric acid used in skincare today is made by fermenting sugars (usually from molasses). This synthetic version is identical to the natural citrus form but easier to stabilize and use in formulations.
Rosacea skin has a lower threshold for acids generally, with 62.5% of rosacea subjects in one study reacting to lactic acid in a sting test. This is why we mark citric acid as a potential rosacea trigger.
However, this ingredient shows up as a pH adjuster or chelator at roughly 0.1-1% in many products. These low levels are unlikely to be an issue for rosacea skin and becomes a potential trigger at exfoliating concentrations (20%). Because everybody's skin is unique, we recommend a patch test if you are unsure.
Dicaprylyl Carbonate comes from carbonic acid and caprylyl alcohol, a fatty alcohol. It is an emollient and gives skin a velvet feel. The sources of Dicaprylyl Carbonate may be synthetic or from animals.
As an emollient, Dicaprylyl Carbonate creates a film on the skin. This film traps moisture in, keeping your skin soft and hydrated.
Ethylhexylglycerin is created from glycerin. It is a multitasker ingredient that:
The CIR Expert Panel found minimal skin absorption or sensitization of any kind in a safety assessment. Though this ingredient is considered well-tolerated, a small number of cases of allergic dermatitis have been published since 2002. Just be sure to patch test if you are unsure.
Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.
Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
Topically, glycerin does several things at once:
Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3.
Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin.
This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products.
Just know very high concentrations (>40%) can feel tacky in low humidity.
Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.
Glycine Soja Oil is a plant-derived oil from soybean seeds. Like other oils, it is rich in essential fatty acids (mostly linoleic and oleic) that support skin hydration and barrier function.
The fatty acids are able to integrate into the lipid matrix of the stratum corneum to help soften skin and reduce water loss.
On top of that, soybean oil is rich in vitamins like vitamin E, a potent antioxidant.
Research on soybean's active components also point to anti-inflammatory, collagen-stimulating, antioxidant activity, and protection against UV-induced oxidative damage.
Most of this research applies to the broader soybean plant and not just the oil fraction alone.
This ingredient may not be fungal acne safe due to the oleic acid content.
Lecithin is a term for a group of substances found in the cell membranes of plants, animals, and humans. They are made up of phospholipids.
Thanks to its amphiphilic structure (water-loving head and oil-loving tail), it is a true multitasker:
It plays well with most ingredients and is typically used at 0.1-1%. However, concentrations up to 50% have been reported in moisturizers.
Phenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).
It has a large spectrum of antimicrobial activity and especially effective bacteria, yeast, and mold while only having a weak effect on your skin's natural microbiome.
On a cellular level, it disrupts the cell membranes of microbes by poking holes that make the cell leak. This shuts down the chemical reactions the microbe needs to make energy so it can no longer survive.
Another perk of this ingredient is that it stays functional across a wide pH range (3-10).
You'll often see it paired with boosters like Ethylhexylglycerin; one study showed that a 1:9 ratio of Ethylhexylglycerin to Phenoxyethanol damages bacterial membranes as effectively as doubling the Phenoxyethanol concentration on its own.
Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.
Safety-wise, the fear mongering does not hold up to the evidence. The EU's Scientific Committee on Consumer Safety and FDA consider it safe as a preservative at up to 1%, including for children of all ages.
Adverse systemic effects only showed up in animal studies at exposures roughly 200x higher than what people get from cosmetics. And despite its very widespread use, this ingredient is a rare sensitizer and allergic reactions are uncommon.
Sodium Phytate is the synthetic salt form of phytic acid. Phytic acid is an antioxidant and can be found in plant seeds.
Sodium Phytate is a chelating agent. Chelating agents help prevent metals from binding to water. This helps stabilize the ingredients and the product.
Tocopherol is a fat-soluble antioxidant known as Vitamin E.
You'll find this ingredient in the vast majority of skincare (for good reason). It works to neutralize free radicals, or unstable molecules generated by UV exposure, pollution, and other environmental stressors, before they can cause oxidative damage to your skin cells.
Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.
It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.
This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.
This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.
In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.
Concentrations usually range from 0.1-1% in most leave-on products.
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!