Josh Rosebrook Daily Acid Toner

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!

Learn about other types of clay, such as Kaolin, Bentonite, or Fuller's Earth.

Here's what the research shows:

In-vitro shows it calms inflammation signals; the most skin-relevant study put a kelp extract on human skin cells and then hit them with inflammatory triggers. The kelp-treated cells produced less of the inflammatory messenger molecules that normally get released.

In a realistic 3D model of skin, the pre-treated tissue held onto its cell-to-cell "seals" better and leaked less water (basically the lab version of a strong vs. weak skin barrier).

Two honest notes: the seal effect only showed up in the 3D model and at higher doses the extract started harming the cells (so more might not be better)

Fucoidan is why kelp gets talked about; it's the sulfated sugar molecule that brands like to name-drop. When four fucoidans were compared, the one from Macrocystis pyrifera was the most active. Just know this was from immune research and not skincare research.

On real people, the numbers look good (with an asterisk). The strongest evidence is all on Macrocystis Pyrifera Ferment inside one company's finished serum and not the plain extract.

Using it twice daily for eight weeks raised skin moisture 16 percent and cut water loss through the skin by 11 percent. A stripping test that repeatedly tapes and peels the skin surface found treated skin held up 30 percent better.

The standout result: half the face was prepped for three weeks and then the whole face got a 70 percent glycolic peel. The prepped side had recovered 71 percent of its barrier versus 23 percent untreated two hours later. A separate review also reported less visible redness and improvement in visible aging measures.

Three asterisk: It's the ferment, not the extract. The kelp isn't necessarily doing all the work since it's the whole formula. And it was funded by The Estée Lauder Companies with several authors on staff.

There's no fixed concentration published for this ingredient but real-world use survey shows this ingredient can be used up to 36%. There's an extra wrinkle for leave-on products since these extracts are usually supplier pre-diluted in water, glycerin, or propanediol.So "5%" on the bottle might mean under 1% for actual kelp solids.

On allergies: kelp is naturally iodine-rich, so people with a known iodine or seafood ingredient sensitivity should patch test.

You'll see algae listed as a 5/5 on a lot of pore-clogging charts and that number doesn't come from anywhere; it's not in the original rabbit-ear studies that most comedogenic ratings trace back to.

The reasoning behind the reputation is that seaweed is high in iodine and iodine can trigger acne-like breakouts when eaten. This traces back to a 1976 letter in Archives of Dermatology describing two women whose breakouts cleared after they stopped taking high-dose kelp supplements orally.

And the reaction of these two women wasn't clogged pores at all: it was an iodine-triggered pustular rash. Later research found normal dietary iodine doesn't meaningfully affect acne either and nobody has shown topical algae delivers enough iodine to matter.

What we do have is dozens of brown and red algae ingredients found to be non-irritating and non-sensitizing, and a handful of studies that found algae compounds may actually help acne.

However, plenty of people do report breaking out from algae-containing products. Skin is individual and it's worth avoiding if yours has reacted to algae before.

What those sugars do is simple and useful: they hold onto water and form a light film on the skin. That means they boost hydration, add a bit of slip, and leave a soft, cushiony feel.

It also helps with texture and thickness.

You'll see claims about anti-aging and "second skin" effects but those come mostly from supplier marketing.

The real research is cell-culture stuff and there's no human trial on this ingredient specifically (yet). So for now, treat it as a nice hydrator and texture helper, not an active.

Safety-wise, it's pretty solid. The Cosmetic Ingredient Review panel rated it safe as used, human sensitization tests came back negative, and it wasn't irritating in skin or eye tests.

Typical use levels are 0.5% or lower.

You'll see algae listed as a 5/5 on a lot of pore-clogging charts and that number doesn't come from anywhere; it's not in the original rabbit-ear studies that most comedogenic ratings trace back to.

The reasoning behind the reputation is that seaweed is high in iodine and iodine can trigger acne-like breakouts when eaten. This traces back to a 1976 letter in Archives of Dermatology describing two women whose breakouts cleared after they stopped taking high-dose kelp supplements orally.

And the reaction of these two women wasn't clogged pores at all: it was an iodine-triggered pustular rash. Later research found normal dietary iodine doesn't meaningfully affect acne either and nobody has shown topical algae delivers enough iodine to matter.

What we do have is dozens of brown and red algae ingredients found to be non-irritating and non-sensitizing, and a handful of studies that found algae compounds may actually help acne.

However, plenty of people do report breaking out from algae-containing products. Skin is individual and it's worth avoiding if yours has reacted to algae before.

Interestingly, the size of the molecule affects its behavior:

Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.

Many serums use a blend of both weights so you can get surface hydration plus longer-lasting and deeper effects.

You'll typically see concentrations between 0.1-2% for this ingredient.

As a cosmetic ingredient, it grabs water and holds it in the upper layers of skin to smooth roughness and ease dehydration.

There's some clinical support for the NMF approach with a study showing that a cream built to mimic the skin's NMF significantly boosted hydration.

Safety-wise, this ingredient non-irritating, non-comedogenic, and non-phototoxic in testing, with minimal skin absorption.

It also works really well with other hydrators like glycerin or hyaluronic acid, and typical usage is somewhere between 0.2-4%.

Some studies have explored oral supplementation of pantothenic acid in the acne context and found it to help reduce blemishes over time.

Though oral and topical use are different, this research helps explain why vitamin B5 is often included in skincare routines aimed at keeping skin balanced and hydrated.

Reviews of this ingredient have found it to be neither a dermal irritant nor a sensitizer.

Fun fact: Proline can be found in protein-rich foods like meat, fish, eggs, and dairy.

It is also used to boost the efficacy of exfoliating actives like AHAs by improving skin feel and reducing irritation potential.

Studies show this ingredient supports hydration through two actions:

1) Limiting water evaporation
2) Enhancing the spreadability of emulsion products to disperse humectants and emollients across the skin's surface

Additionally, galactoarabinan can improve makeup wear and reduce "tightness" after cleansing.

Many components of tea have anti-inflammatory properties. Polyphenols and L-theanine help soothe the skin and reduce irritation. L-theanine is an amino acid that makes up most of the amino acids found in tea leaves. The caffeine in Camellia Sinensis Leaf Extract helps calm inflamed blood vessels.

Research has shown both drinking Camellia Sinensis Leaf Tea (green tea, white tea, oolong, black tea) and applying it to the skin can help boost skin elasticity and hydration. Studies also show using tea extract may reduce sebum, or oil, production.

Calendula Officinalis Flowers may help soothe your skin by reducing inflammation. Emerging studies show it inhibits NO production safely, therefore reducing inflammation.

Marigolds have been used in traditional medicine throughout Asia and Europe.

Antioxidant components in chamomile help fight free-radical molecules. These unstable molecules may damage your skin cells. By stabilizing them, antioxidants may help reduce the signs of aging.

Ancient Greeks, Romans, and Egyptians used Chamomile to treat skin redness and dryness. Chamomile has also been used to help with stomach issues.

Studies show green tea extract and its catechins (like epigallocatechin gallate (EGCG)) help your skin cells product energy more efficiently and reducing the number of free-radicals that can damage your skin from the inside.

In lab-grown skin models, this translated to younger, healthier, and stronger skin.

There's also good sun protection data; researchers saw less DNA damage and redness on human skin when green tea was applied before UVB exposure. And the more they applied, the better the protection.

Needless to say, this ingredient shouldn't replace your sunscreen. But it is a great supportive ingredient that you can already find in many sunscreens and antioxidant serums.

A 2009 study found a 2% green tea lotion was effective for mild-to-moderate acne thanks to its anti-inflammatory and mild antimicrobial activity.

The quality of the extract matters a lot here:

Good extracts contain 50-90% catechins while lower quality ones are mostly there for marketing. We recommend reaching out to the brand if you have questions about the quality or source of their ingredients.

Human Repeated Insult Patch Testing showed no irritation or sensitization at use concentrations (0.86% in leave-on products and up to 30% as leaf water).

Glycolic acid removes the top layer of dead skin cells to allow newer and fresher ones to emerge.

AHAs work by breaking down the structural “glue” that holds old skin cells in place. When that buildup is gone, your skin can renew itself more efficiently.

Research also shows glycolic acid stimulates collagen production, helping to firm and thicken the skin over time. This is one of its biggest advantages over other AHAs.

Overall, glycolic acid helps with:

Fun fact: Glycolic acid boosts skin hydration by helping it produce molecules that increase hyaluronic acid naturally.

To work best, glycolic acid products should have a pH between 3-4 (that’s where exfoliation is most effective but still gentle on skin).

The pH and concentration of a product are key to its effectiveness:

It is normal to feel a slight stinging sensation when using glycolic acid. This usually fades as your skin adjusts.

Because glycolic acid has the smallest molecular size in the AHA family, it can penetrate deeper, which enhances its effectiveness but also makes it more likely to irritate sensitive skin.

If your skin is very sensitive or prone to rosacea, glycolic acid may be too strong; in that case, try milder options like lactic acid or a PHA instead.

Recent studies suggest glycolic acid might even help protect against UV damage. But don’t skip sunscreen! Freshly exfoliated skin is more sensitive to the sun.

Glycolic acid is a skincare superstar. It smooths, brightens, hydrates, and firms the skin. Unless you’re highly sensitive, it’s well worth adding to your routine.

Read more about some other popular AHA's here:

This ingredient has antimicrobial properties and helps prevent the growth of bacteria in a product.

Leuconostoc is used to make the traditional Korean side-dish, kimchi. It is also used to make sourdough bread (both incredibly yummy foods).

Like other alcohols, this ingredient helps prevent the growth of bacteria. However, its main purpose is to impact a fragrance.

Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.