Sarah Ford Biocell Intensive Moisturizer

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.

You might have heard of "niacin flush", or the reddening of skin that causes itchiness. Niacinamide has not been found to cause this.

In very rare cases, some individuals may not be able to tolerate niacinamide at all or experience an allergic reaction to it.

If you are experiencing flaking, irritation, and dryness with this ingredient, be sure to double check all your products as this ingredient can be found in all categories of skincare.

When incorporating niacinamide into your routine, look out for concentration amounts. Typically, 5% niacinamide provides benefits such as fading dark spots. However, if you have sensitive skin, it is better to begin with a smaller concentration.

When you apply niacinamide to your skin, your body converts it into nicotinamide adenine dinucleotide (NAD). NAD is an essential coenzyme that is already found in your cells as "fuel" and powers countless biological processes.

In your skin, NAD helps repair cell damage, produce new healthy cells, support collagen production, strengthen the skin barrier, and fight environmental stressors (like UV and pollution).

Our natural NAD levels start to decline with age, leading to slower skin repair, visible aging, and a weaker skin barrier. By providing your skin niacinamide, you're recharging your skin's NAD levels. This leads to stronger, healthier, and younger looking skin.

Another name for vitamin B3 is nicotinamide. This vitamin is water-soluble and our bodies don't store it. We obtain Vitamin B3 from either food or skincare. Meat, fish, wheat, yeast, and leafy greens contain vitamin B3.

The type of niacinamide used in skincare is synthetically created.

This is due to how structurally similar it is to what your skin already produces.

Though it is mostly an emollient that helps soften and hydrate skin, it also has some humectant and occlusive action. Humectants help the skin retain moisture while occlusives seal it in, making squalane a triple-threat moisturizer.

Research shows it has antioxidant capabilities that help protect against stressors like UV exposure, specifically UVA induced oxidative stress. This study also found that it supports collagen biosynthesis in human dermal fibroblasts.

No clinical study has reported significant adverse effects and irritation reactions are very rare from this ingredient (even at 100% concentration).

Overall, it's a fantastic ingredient for hydration and is suitable for all skin types.

This depends on the source. Squalane can be derived from both plants and animals. Most squalane used in skincare comes from plants.

Please note: the source of squalane is only known if disclosed by the brand. We recommend reaching out to the brand if you have any questions about their squalane.

Read more about squalene with an "e".

Though squalane is often called an oil, it’s technically not one. It is a hydrocarbon, meaning it is only made of carbon and hydrogen. True oils are triglycerides and made of fatty acids and glycerol.

The term “oil-free” isn’t regulated so companies can define it however they want. Some exclude all oils, while others just avoid mineral oil or comedogenic oils.

Squalane has a comedogenic rating of 1 from the original 1972 study that tested raw ingredients under occlusion on rabbit ears. This system is not standardized or peer-reviewed, and using the raw ingredients is very different from how diluted cosmetic formulations are used on human skin.

A comedogenic rating of 1 means it is "unlikely to clog pores" according to the original rating system.

The overall formula of a product matters more than the individual ingredients on whether or not it will cause clogged pores.

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.

Our skin makes fewer of them as we age. This is a big part of why older skin heals slower and looks less bouncy.

The idea behind putting them in skincare is to "top up" the supply from the outside.

"Conditioned media" sounds mysterious but it's basically just leftover broth.

They're made in a lab where scientists grow human skin cells (fibroblasts) in a nutrient liquid. These cells release a cocktail of helpful proteins into that liquid as they live and grow.

Then, these cells are filtered out and the ingredient is the "conditioned" liquid now full of secreted goodies.

So what does neonatal mean here? It just means the original cells came from newborn tissue (usually donated foreskin), which tend to be younger, more active, and better at pumping out growth factors than adult cells.

Technically, this isn't one single ingredient, it's a mix of dozens of active molecules working together, including:

Studies find growth factor conditioned media can help with:

The evidence behind this ingredient is pretty solid too (and not just marketing).

A 24 week study of a fibroblast conditinoed media serum showed measurable improvements in the look of photodamaged skin, and these results were backed by actual skin biopsies rather than just before/after photoshoots.

And a broader review that pulled together many growth factor studies came to a similar conclusion: they generally help with fine lines, texture, firmness, and are well-tolerated.

It's also worth knowing the caveat that the review pointed out most of these serums also contained peptides, antioxidants, and exosomes.

The honest answer is there isn't a tidy "use at 1-2%" number the way there is for something like niacinamide.

This is because conditioned media isn't a single molecule. Brands add it as a percentage of a finished formula so that number is all over the map.

The serums built around it usually advertise very high levels (~50%) while others just use a splash. And the individual growth factors floating inside are actually present in very tiny amounts (think nano/micrograms per gram).

Here's one regulatory anchor point: the FDA has approved a wound healing gel that uses a pure growth factor at 0.01% (100 micrograms per gram). This shows the active growth factors themselves work at very low concentrations.

So the "50%" numbers you see on labels refer to the diluted broth and not the pure proteins.

The single most important thing to understand growth factors is that they are very fragile.

Dr. Zoe Draelos wrote this about them for Dermatology Times:

Independent lab work backs up the fragility.

Many growth factors lose a big chunk of their activity within a day or two sitting in water at room temperature and this is why smart formulating matters so much. Airless pumps, water-free formulas, and cool storage all help the ingredient survive long enough to do something. It's also a green flag if a brand can show real stability testing.

None of this means growth factor serums don't work; plenty of people get lovely results. It just means the formulation and packaging are doing a lot of the heavy lifting.

You may have heard a worry that growth factors "feed" skin cancer because their whole job is to encourage cells to multiply (this is called mitogenic activity).

It's a fair question to ask so here's the actual picture.

The theoretical concern is real enough that dermatologists take it seriously. There IS a hypothetical worry that they can encourage the wrong cells to grow in skin that already has sun damage or pre-cancerous spots.

Due to this, the cautious advice is to check with your dermatologist before using growth factor products if you have psoriasis, a history of skin cancer, or a lot of pre-cancerous sun damage.

Now the reassuring side:

There has been no documented pattern of growth factor products causing skin cancers despite millions of units sold over many years.

A large safety review of pure PDGF (one of the growth factors in these blends) found it to be non-toxic, non-mutagenic, and non-carcinogenic across decades of medical use. This is including repeated daily application to open wounds.

And a dermatology review specifically looking at topical EGF found no evidence that it stimulates cancer cells to grow (partly because these proteins are large and mostly stay near the surface).

The bottom line for a healthy person with no specific risk factor:

Growth factor conditioned media has a strong track record and is generally considered safe and well tolerated.

But be sure to loop in your dermatologist first if you have psoriasis, active or past skin cancer, or heavy sun damage. This is not because it's proven dangerous but because it's a sensible precaution while the long-term research keeps building.

The US allows human-derived growth factors so Human Neonatal Fibroblast Conditioned Media appears on labels.

In the EU, human-cell-derived ingredients are banned in cosmetics. EU products use plant-derived alternatives (barley is a common one) to get a similar effect.

D-panthenol is also known as dexpanthenol. Most cosmetics use dexpanthenol or a mixture of D and L-panthenol.

Panthenol is famous due to its ability to go deeper into the skin's layers. Using this ingredient has numerous pros (and no cons):

Like hyaluronic acid, panthenol is a humectant. Humectants are able to bind and hold large amounts of water to keep skin hydrated.

This ingredient works well for wound healing. It works by increasing tissue in the wound and helps close open wounds.

Once oxidized, panthenol converts to pantothenic acid. Panthothenic acid is found in all living cells.

This ingredient is also referred to as pro-vitamin B5.

Specifically, saccharide Isomerate is a humectant. Humectants draw moisture from the air to our skin.

Research shows Saccharide Isomerate to be an effective moisturizer.

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.

Read more about some other popular AHA's here:

The acidity of our skin is maintained by our glands and skin biome; normal pH level of skin is slightly acidic (~4.75-5.5).

Being slightly acidic allows our skin to create an "acid mantle". This acid mantle is a thin barrier that protects our skin from bacteria and contaminants.

Fun fact: Erythritol can be naturally found in some fermented foods.

That's where Acetyl Tetrapeptide-40 comes in. It turns down the signals that cause this inflammatory overreaction. As a bonus, keeping inflammation in check also protects collagen and other structural proteins from being broken down by enzymes.

According to a manufacturer, this ingredient also calms UV-related inflammation and helps reduce excess pigment production.

This ingredient is considered safe for all skin types and has been shown to work at low concentrations (0.05%).

Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).

It's actually inactive on its own and works like a slow-release "storage" form; the enzymes in your skin called esterases gradually convert it into active vitamin E over time.

One in vivo study showed 5% of the acetate in the living layer of the epidermis converted to vitamin E after 5 days of application. This study also found the skin gained protection against UV damage even though the conversion was slow and small.

Once converted, vitamin E acts as a skin's main fat-soluble antioxidant that fights free radicals to protect skin from damage.

Topical vitamin E generally boosts the skin's photoprotection, and it reduced UV-damage in animal models.

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.

Overall, it has a pretty solid safety profile and has been found to be non-irritating and non-comedogenic. Allergic reactions may happen but stay rare due to how widely the ingredient gets used.

The concentration will vary depending on the formula; industry data shows 0.1% in baby lotions, 3% in lipsticks, and 5% in foot powders. You can also find this ingredient at 100% in a pure vitamin E oil.

Most leave-on skincare keeps it at the lower end, often between 0.5-1%.

Because it’s oil-soluble, THD dives deep into your skin’s fatty layers (think ceramides and cholesterol) to fight off the kind of free radicals that mess with your skin barrier. This makes it a great pair with water-based vitamin C (ascorbic acid) that mainly works on the surface.

Even at just 0.1%, THD is already showing great antioxidant activity. When used up to 2%, it helps keep your skin happy and calm, especially when it’s stressed from pollution or sun.

Want to fade dark spots or tackle hyperpigmentation? You’ll want 5% or more. Pairing it with brightening buddies like niacinamide or licorice root gives even better results. One study even used 30% THD with other brighteners and saw real results on stubborn discoloration, even in melasma-prone skin.

A note on THD: It’s has a slightly silky, oily texture and usually shows up colorless or pale yellow (though the exact shade can vary by supplier).

While you can sneak it into water-based formulas, it really shines when paired with silicones or oils, which help your skin soak it up better.

THD is pretty stable, but it’s still vulnerable to degradation like ascorbic acid. Too much light or heat (above 113°F / 45°C) can break it down over time. Go for dark and opaque packaging that keeps it safe and shady!

Read more about other types of Vitamin C:

The CIR Expert Panel assessed the safety of 126 acrylates copolymers and concluded they are safe in cosmetics at current use levels when formulated to be non-irritating. They also noted the levels present in finished cosmetic products are not considered a safety risk and Genotoxicity testing (Ames tests, chromosomal aberration assays) has come back negative across the board.

Though the raw building blocks (like acrylic acid) can be irritating on their own, cosmetic-grade versions go through purification to keep levels extremely low.

Sodium Acrylates Copolymer is a large molecule that doesn't penetrate skin barrier in any meaningful way.

It plays well with most ingredients and is typically used at 0.1-1%. However, concentrations up to 50% have been reported in moisturizers.

Caprylhydroxamic Acid is often used with natural antimicrobial products as an alternative to preservatives.