Penny Lane Organics Extreme Moisturizing Cream

This is why Europe's medicines regulator has approved calendula extracts as a traditional remedy for minor skin inflammation and healing small wounds.

The stronger human evidence is around would/ulcer care rather than everyday cosmetic claims; a review that pulled together 14 studies found that calendula helped calm the early, inflamed stage of a wound and helped new skin tissue form faster.

Two studies also showed it shrank leg ulcers (the kind caused by poor circulation). Results were mixed for burns and for the skin irritation people get from radiation treatment, so it's not a sure thing there.

In cosmetics, it's mostly a skin conditioning and soothing agent.

The Cosmetic Ingredient Review panel concluded that calendula-derived ingredients are safe as used and that the ingredients are not irritating, sensitizing, or photosensitizing in clinical tests (though they may be mild eye irritants).

Typical use levels are quite low; industry data reported it used at under 0.5% (one supplier noted a 10-25% extract blend used at 1-10% in the finished product). Historical use goes up to 10%.

The only thing to keep in mind is if you have daisy/ragweed allergies. Calendula is in the same family and one patch-test study found 2% of dermatitis patients reacted to marigold. Be sure to patch test if you have sensitive or allergy-prone skin.

Vitamin E is also prevalent in this ingredient and the most dominant form is gamma-tocopherol.

These compounds give the ingredient emollient and skin conditioning properties that keep the skin soft and hydrated.

There's no regulatory maximum cap for this ingredient so you'll see it across a huge concentration range (100% as a single ingredient facial oil).

On allergies: refined cosmetic-grade oils carry almost no protein. The CIR notes that people allergic to a food generally do not react to the refined oil because the allergenic protein does not partition into it (though cold-pressed grades retain more).

However, it's worth patch testing if you have a stone fruit or tree nut allergy because manufacturer processes for removing the protein can vary.

Malassezia lacks the cytosolic fatty acid synthase gene so the yeast cannot make palmitate on its own and instead uses lipases and phospholipases to release fatty acids from host lipids. Since apricot kernel oil is entirely C16-18 (right in the usable range of C11-24), this ingredient may not be fungal acne safe.

Old rabbit-ear testing did assign this ingredient a comedogenic rating of 1-2. The original author has stated that testing on rabbit ears is not an ideal model for human comedogenicity.

Human testing has proved that any finished product with a comedogenic ingredient won't automatically make you break out; it really comes down to concentration, formula, and your skin.

Just know high-oleic oils tend to feel heavier on oily skin so it's worth patch testing.

Unlike other plant oils, jojoba wax doesn't easily penetrate skin. It mostly works in the uppermost layers as an emollient. This just means it forms a light barrier on the skin to help retain moisture.

Formulations with jojoba esters up to 90% reduced transepidermal water loss (TEWL) and increased barrier recovery by 81% (outperforming bisabolol at 47%).

Besides barrier support, the science also suggests jojoba to have anti-inflammatory effects and potential applications for skin infections, aging, and wound healing.

Fun fact: Indigenous cultures have used jojoba as a moisturizer and to help treat burns for centuries.

Fungal acne: The Malassezia yeast is known to metabolize fatty acids in the C11-24 range and jojoba's dominant fatty acid components fall into this range. This ingredient may not be fungal acne safe.

Another interesting compound that makes it stand out from other oils is the trace amount of all-trans retinoic acid (the same molecule as prescription tretinoin), along with some carotenoids and tocopherols.

The linoleic acid is a precursor to ceramide 1, one of the essential lipids in the stratum corneum. Topical linoleic acid application has been shown to improve barrier function and reduce comedone size in clinical studies.

One study found that linoleic acid and alpha-linoleic acid lighten UV-induced hyperpigmentation. A 2015 study found that participants who used rosehip twice daily for eight weeks saw improvements in crow's feet, skin moisture, and skin elasticity compared to the placebo.

If you're hoping to get tretinoin benefits from this ingredient, it's worth noting the trans-retinoid acid is trace-level and minimal compared to the amount of retinol or tretinoin found in formulas.

A 2024 review highlighted the fatty acid composition in rosehip-based dermatological products for:

Typical usage rates range from 1-100% with 5-10% being the most common in moisturizers.

Since the oil is high in polyunsaturated fatty acids, it's prone to oxidation. Look for formulations stabilized with ingredients like vitamin E and be sure to store away from light/heat.

Fungal acne: This oil is not considered fungal acne safe because dominant fatty acids fall into the C11-24 range that Malassezia can metabolize.

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!

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.

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.