No. 28 Primer Serum
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Hourglass No. 28 Primer SerumIngredients explained
A super commonly used 5 unit long, cyclic structured silicone that is water-thin and does not stay on the skin but evaporates from it (called volatile silicone). Similar to other silicones, it gives skin and hair a silky, smooth feel.
It's often combined with the non-volatile (i.e. stays on the skin) dimethicone as the two together form a water-resistant, breathable protective barrier on the skin without a negative tacky feel.
Probably the most common silicone of all. It is a polymer (created from repeating subunits) molecule and has different molecular weight and thus different viscosity versions from water-light to thick liquid.
As for skincare, it makes the skin silky smooth, creates a subtle gloss and forms a protective barrier (aka occlusive). Also, works well to fill in fine lines and wrinkles and give skin a plump look (of course that is only temporary, but still, it's nice). There are also scar treatment gels out there using dimethicone as their base ingredient. It helps to soften scars and increase their elasticity.
As for hair care, it is a non-volatile silicone meaning that it stays on the hair rather than evaporates from it and smoothes the hair like no other thing. Depending on your hair type, it can be a bit difficult to wash out and might cause some build-up (btw, this is not true to all silicones, only the non-volatile types).
A thick, high molecular weight silicone that is usually diluted in another, lighter silicone fluid (like dimethicone or cyclopentasiloxane). The dimethiconol containing silicone blends leave a silky smooth, non-greasy film on the skin.
A silicone fluid that gives a nonoily, easy to spread emolliency to the formulas. It is also used as a water repellent additive and to reduce the tackiness and stickiness of other ingredients. It also imparts gloss, softness and better manageability to hair.
One of the many types of ceramides that can be found naturally in the upper layer of the skin. Ceramides make up about 50% of the goopy stuff that's between our skin cells and play a super important role in having a healthy skin barrier and keeping the skin hydrated. It works even better when combined with its pal, Ceramide 1.
We wrote way more about ceramides at ceramide 1, so click here to know more.
Jojoba is a drought resistant evergreen shrub native to South-western North America. It's known and grown for jojoba oil, the golden yellow liquid coming from the seeds (about 50% of the weight of the seeds will be oil).
At first glance, it seems like your average emollient plant oil: it looks like an oil and it's nourishing and moisturizing to the skin but if we dig a bit deeper, it turns out that jojoba oil is really special and unique: technically - or rather chemically - it's not an oil but a wax ester (and calling it an oil is kind of sloppy).
So what the heck is a wax ester and why is that important anyway? Well, to understand what a wax ester is, you first have to know that oils are chemically triglycerides: one glycerin + three fatty acids attached to it. The fatty acids attached to the glycerin vary and thus we have many kinds of oils, but they are all triglycerides. Mother Nature created triglycerides to be easily hydrolyzed (be broken down to a glycerin + 3 fatty acid molecules) and oxidized (the fatty acid is broken down into small parts) - this happens basically when we eat fats or oils and our body generates energy from it.
Mother Nature also created wax esters but for a totally different purpose. Chemically, a wax ester is a fatty acid + a fatty alcohol, one long molecule. Wax esters are on the outer surface of several plant leaves to give them environmental protection. 25-30% of human sebum is also wax esters to give us people environmental protection.
So being a wax ester results in a couple of unique properties: First, jojoba oil is extremely stable. Like crazy stable. Even if you heat it to 370 C (698 F) for 96 hours, it does not budge. (Many plant oils tend to go off pretty quickly). If you have some pure jojoba oil at home, you should be fine using it for years.
Second, jojoba oil is the most similar to human sebum (both being wax esters), and the two are completely miscible. Acne.org has this not fully proven theory that thanks to this, jojoba might be able to "trick" the skin into thinking it has already produced enough sebum, so it might have "skin balancing" properties for oily skin.
Third, jojoba oil moisturizes the skin through a unique dual action: on the one hand, it mixes with sebum and forms a thin, non-greasy, semi-occlusive layer; on the other hand, it absorbs into the skin through pores and hair follicles then diffuses into the intercellular spaces of the outer layer of the skin to make it soft and supple.
On balance, the point is this: in contrast to real plant oils, wax esters were designed by Mother Nature to stay on the surface and form a protective, moisturizing barrier and jojoba oil being a wax ester is uniquely excellent at doing that.
The oil coming from the seeds of dog-rose, a wild rose species native to Europe, northwest Africa and western Asia. It's a nice emollient, moisturizing plant oil loaded with skin-nourishing fatty acids (linoleic acid - 51%, linolenic acid - 19% and oleic acid - 20%).
If you start to dig a bit deeper into the rosehip oil topic, you will soon see that there are lots of species of rose, and it's all a bit confusing to know what the differences and similarities between the oils of the different roses are. As far as our research can tell, here is the gist.
In skincare two major types of rosehip oil are used:
1. Rosa Rubiginosa that is a synonym for Rosa Eglanteria and for Rosa Mosqueta. We will call it RR from now on.
2. Rosa Canina, or RC
The oil content and composition of RR and RC is similar, but there are some differences: RR contains 8% of oil, while RC contains a bit more, 10%. However, the quality of RR oil seems to be a bit better: it contains 78% essential unsaturated fatty acids while RC contains only 71%. Also, the linoleic-oleic ratio of RR is better (3.3 vs 2.5) that might be important if your skin is acne-prone (as linoleic acid is good for acne and oleic is not).
There is one more important thing to mention: RR oil is famous for containing the miracle active, tretinoin. Though Wikipedia puts RR and RC oil under the same article called as Rose hip seed oil, the referenced research about tretinoin content examines only Rosa Rubiginosa. We looked for a research paper explicitly stating that Rosa Canina also contains tretinoin, but could not find one, so we can neither deny nor confirm it. What we could find is a paper mentioning the tocopherols (vitamin E) and carotenoids (pro-vitamin A) content of Rosa Canina oil that gives it some nice antioxidant properties.
All in all, it is a great emollient plant oil with great fatty acids beneficial for any skin type.
The oil coming from the seeds of the nice, little, yellow-flowered plant called Evening Primrose. Similar to other plant oils, it's loaded with nourishing and moisturizing fatty acids. It's a very rich source of linoleic acid (66-76%), and also contains the soothing and healing superstar fatty acid, gamma-linolenic acid (aka GLA, 7-12%) (Btw, the richest known source of GLA is the borage oil, but evening primrose still counts as a very good source of it). It also contains oleic acid, but not too much around 6-15%.
Since the 1980's, EPO is a well-known food supplement and there are quite a lot of studies examining what happens if you take it orally. It seems to be helpful with a bunch of things: atopic dermatitis, dry eyes, brittle nails, sunburn and even acne.
As for the skin, it's a great hydrating plant oil, that can also reduce inflammation and irritation. It's a superb healing agent that can truly help dry skin, not just on the surface by covering it (and not letting water to evaporate) but by initiating structural changes within the skin. If that's not enough, it also helps skin cell regeneration.
All in all, a real goodie especially for dry, easily irritated skin.
The emollient plant oil that comes from almonds. Similar to other plant oils, it is loaded with skin-nourishing fatty acids (oleic acid - 55-86% and linoleic acid 7-35%) and contains several other skin goodies such as antioxidant vitamin E and vitamin B versions.
It's a nice, basic oil that is often used due to its great smoothing, softening and moisturizing properties. It's also particularly good at treating dry brittle nails (source).
We don't have description for this ingredient yet.
You probably know olive oil from the kitchen as a great and healthy option for salad dressing but it's also a great and healthy option to moisturize and nourish the skin, especially if it's on the dry side.
Similar to other emollient plant oils, it's loaded with nourishing fatty acids: oleic is the main component (55-83%), and also contains linoleic (3.5-20%) and palmitic acids (7-20%). It also contains antioxidant polyphenols, tocopherols (types of vitamin E) and carotenoids and it's one of the best plant sources of skin-identical emollient, Squalene.
Overall, a great option for dry skin but less so for acne-prone or damaged skin.
It's the oil that comes from the edible hazelnuts. Just like many other plant oils, it's a great emollient, moisturizer, skin softener. It has a light skin feeling, spreads easily and absorbs quickly into the skin. It's rich in nourishing fatty acid, oleic containing about 66-85%.
We feel that this one is a bit under the radar probably because the Borage plant is not very well known. Maybe because its name isn't as cool as some others, it's hard to compete with kukui or baobab, not to mention murumuru. But let us tell you when it comes to skin care, borage seed oil is one of the best oils that can happen to your skin. Especially, if it's dry, sensitive, easily irritated, often itchy or eczema prone.
So what is so special about it? It is the richest known plant source of the super important essential fatty acid, gamma-linolenic acid (GLA). GLA is soothing and nourishing, and can repair even severely dry and irritated skin, but it's pretty rare and borage contains by far the most of it (17-28%). Next to GLA, it also contains more common fatty acids, like linoleic (36%), oleic (18%) or palmitic acid (10%).
If your skin is dry and sensitive, this one is totally for you.
Having such a cool name and coming from Hawaii how could this oil be not good? Well, it is good. It's absorbed excellently by the skin and is used traditionally by the Hawaiians to soothe sunburn and other inflammations.
Research confirms this: it's shown to have anti-inflammatory, pain reducing, and wound healing properties. It's also a particularly rich source of moisturizing essential fatty acids linoleic and linolenic (about 42 and 32%) and it's not so rich in oleic acid - around 15% - that can be good even for acne prone skin.
We don't have description for this ingredient yet.
- Primary fat-soluble antioxidant in our skin
- Significant photoprotection against UVB rays
- Vit C + Vit E work in synergy and provide great photoprotection
- Has emollient properties
- Easy to formulate, stable and relatively inexpensive
It's an ester form of vitamin A (retinol + palmitic acid) that belongs to the "retinoid family". The retinoid family is pretty much the royal family of skincare, with the king being the FDA-approved anti-aging ingredient tretinoin. Retinol is also a very famous member of the family, but it's like Prince George, two steps away from the throne. Retinyl palmitate will be then Prince Charlotte (George's little sister), quite far (3 steps) away from the throne.
By steps, we mean metabolic steps. Tretinoin, aka retinoic acid, is the active ingredient our skin cells can understand and retinyl palmitate (RP) has to be converted by our metabolic machinery to actually do something. The conversion is a 3 step one and looks like this:
retinyl palmitate --> retinol -- > retinaldehyde --> all-trans-retinoic acid
As we wrote in our lengthy retinol description the problem is that the conversion is not terribly effective. The evidence that RP is still an effective anti-aging ingredient is not very strong, in fact, it's weak. Dr. Leslie Baumann in her fantastic Cosmetic Dermatology book writes that RP is topically ineffective.
What's more, the anti-aging effectiveness is not the only questionable thing about RP. It also exibits questionable behaviour in the presence of UV light and was the center of a debate between the non-profit group, EWG (whose intentions are no doubt good, but its credibility is often questioned by scientists) and a group of scientists and dermatologists lead by Steven Q. Wang, MD, director of dermatologic surgery at Memorial-Sloan Kettering Cancer Centre.
Dr. Leslie Baumann wrote a great review of the debate and summarized the research available about retinyl palmitate here. It seems that there is a study showing RP being photo protective against UVB rays but there is also a study showing RP causing DNA damage and cytotoxicity in association with UVA.
We think that the truth lies somewhere in the middle, and we agree with Dr. Baumann's conclusion: "sufficient evidence to establish a causal link between RP and skin cancer has not been produced. Nor, I’m afraid, are there any good reasons to recommend the use of RP". We would add especially during the day!
Bottom line: If you wanna get serious about retinoids, RP is not your ingredient (retinol or tretinoin is!). However, if you use a product that you like and it also contains RP, there is no reason to throw it away. If possible use it at night, just to be on the safe side.
We don't have description for this ingredient yet.
A form of skincare superstar, vitamin C. Even though we are massive vitamin C fans, Ascorbyl Palmitate (AP) is our least favorite. (Btw, if you do not know what the big deal with vitamin C is then you are missing out. You must go and read our geeky details about it.)
So, AP is one of the attempts by the cosmetics industry to solve the stability issues with vitamin C while preserving its benefits, but it seems to fall short on several things.
What's the problem?
Firstly, it's stability is only similar to that of pure ascorbic acid (AA), which means it is not really stable. A great study in the Journal of Cosmetic Dermatology compared a bunch of vitamin C derivatives and this derivative was the only one where the study said in terms of stability that it's "similar to AA". Not really that good.
Second, a study that examined the skin absorption of vitamin C found that ascorbyl palmitate did not increase the skin levels of AA. This does not mean that ascorbyl palmitate cannot penetrate the skin (because it can, it's oil soluble and the skin likes to absorb oil soluble things) but this means that it's questionable if ascorbyl palmitate can be converted into pure Vit C in the skin. Even if it can be converted, the palmitate part of the molecule is more than the half of it, so the efficacy will not be good and we have never seen a serum that contains a decent (and proudly disclosed) amount of AP. We are highly skeptical what effect a tiny amount of AP has in a formula.
Third, another study that wanted to examine the antioxidant properties of AP was surprised to find that even though AP does have nice antioxidant properties; following UVB radiation (the same one that comes from the sun) it also promotes lipid peroxidation and cytotoxicity. It was only an in-vitro study meaning that it was done on cell cultures and not on real people, but still, this also does not support the use of AP too much.
The only good thing we can write about Ascorbyl Palmitate is that there is an in-vitro (made in the lab, not on real people) study showing that it might be able to boost collagen production.
Regarding the skin-brightening properties of pure vitamin C, this is another magic property AP does not have, or at least there is no data, not even in-vitro, about it.
Overall, Ascorbyl Palmitate is our least favorite vitamin C derivative. It is there in lots of products in tiny amounts (honestly, we do not really understand why), however, we do not know about any vitamin C serum featuring AP in high amounts. That is probably no coincidence. If you are into vitamin C, you can take a look at more promising derivatives here.
- Works best between a concentration of 5-20%
- Boosts the skin’s own collagen production
- Fades pigmentation and brown spots
- If used under sunscreen it boosts its UV protection
- Extremely unstable and oxidizes very easily in presence of light or air
- Stable in solutions with water only if pH is less than 3.5 or in waterless formulations
- Vit E + C work in synergy and provide superb photoprotection
- Ferulic acid doubles the photoprotection effect of Vit C+E and helps to stabilize Vit C
- Potent Vit. C serums might cause a slight tingling on sensitive skin
A clear, slightly yellow, odorless oil that's a very common, medium-spreading emollient. It makes the skin feel nice and smooth and works in a wide range of formulas.
We don't have description for this ingredient yet.
A smallish polymer molecule (created from repeated units of Polyethylene glycol, aka PEG) that's used as a solubilizer and viscosity control agent.
It is a clear, colorless liquid that is water-soluble and water-binding (aka humectant) and can help to solubilize sparingly-water soluble things (e.g. vanilla, perfumes) into water-based formulas. Thanks to its water-binding ability, it also prevents the drying out of formulas, especially when combined with the fellow hygroscopic agent, sorbitol.
A clear, colorless oily liquid that works as a medium feel emollient. It absorbs very quickly into the skin, leaves no shine and gives a nice, velvety after-feel.
An emollient ester (basically an oil like liquid) with a light, elegant and silky feel. It gives a matte finish to the products.
It often comes together with two other esters (called Tridecyl Stearate and Tridecyl Trimellitate) as the three of them can be blended so that they mimic very closely the aesthetic and textural properties of controversial, but nice feeling mineral oil.
A viscous, thick liquid emollient that gives lubricity and cushion at low use levels. It's great for night creams, eye area products, and skin treatment products due to the substantive film forming ability.
We don't have description for this ingredient yet.
Citric acid comes from citrus fruits and is an AHA. If these magic three letters don’t tell you anything, click here and read our detailed description on glycolic acid, the most famous AHA.
So citric acid is an exfoliant, that can - just like other AHAs - gently lift off the dead skin cells of your skin and make it more smooth and fresh.
There is also some research showing that citric acid with regular use (think three months and 20% concentration) can help sun-damaged skin, increase skin thickness and some nice hydrating things called glycosaminoglycans in the skin.
But according to a comparative study done in 1995, citric acid has less skin improving magic properties than glycolic or lactic acid. Probably that’s why citric acid is usually not used as an exfoliant but more as a helper ingredient in small amounts to adjust the pH of a formulation.
We have to start by writing how fascinated we are by the amazing lavender fields of Provance and we do love pretty much everything about lavender: its look, its color, its scent.... but, when it comes to skincare, lavender is a questionable ingredient that you probably do not want in your skincare products.
First, let us start with the pros: it has a lovely scent, so no wonder that it is popular as a fragrance ingredient in natural products wanting to be free from synthetic fragrances but still wanting to smell nice. The scent of lavender is famous for having calming and relaxing properties and some smallish scientific studies do support that. Inhaled volatile compounds seem to have a soothing effect on the central nervous system and studies have shown that lavender aromatherapy can improve patient's anxiety and experience in hospitals.
Another pro is that lavender oil has some nice antimicrobial and antibacterial properties. It also has some local pain relieving and muscle relaxing magical powers. Lavender oil is also often claimed to have anti-inflammatory properties. We have found a study confirming this but it was the essential oil of the leaves and not the much more commonly used flowers and the two differ in their main chemical compounds very much. (The main components of the flower essential oil are linalyl acetate and linalool [around 80% the two together] while it is 1,8-Cineole [around 65%] in the essential oil of the leaves.)
Now, let us look at the cons: similar to a bunch of other essential oils, the main components of lavender oil are potentially irritating fragrant components. The two main components are linalyl acetate (about 50%) and linalool (about 35%) and both autoxidise on exposure to the air forming strong contact allergens. To make things even worse, lavender oil seems to be cytotoxic from concentrations as low as 0.25% (concentration up to 0.125% were ok).
There is also an often cited Japanese study that made patch tests with lavender oil for 9 years and found a huge increase in lavender oil sensitivity in 1997 (from 1.1% in 1990 to 8.7% in 1997 and 13.9% in 1998). This was the year when using dried lavender flowers in pillows, wardrobes, and elsewhere became fashionable in Japan, so it seems that increased exposure to lavender results in increased risk of sensitivity.
Overall, it makes us sad to write bad things about such a lovely plant, but when it comes to skincare, you will be better off without lavender.
The fragrant essential oil coming from the whole plant of Rose Geranium. It has a lovely scent with a mix of rose and citrus.
Like most essential oils, it contains antioxidant and antimicrobial components, but the main ones are fragrant constituents (like geraniol and citronellol). Be careful with it, if your skin is sensitive.
We don't have description for this ingredient yet.
We don't have description for this ingredient yet.
The essential oil coming from the rind of the orange (the sweet one). In general, the main component of citrus peel oils is limonene (83-97% for sweet orange peel), a super common fragrant ingredient that makes everything smell nice (but counts as a frequent skin sensitizer).
Other than that, citrus peel also contains the problematic compound called furanocoumarin that makes them mildly phototoxic. Orange peel contains less of it than some other citruses (like bergamot or lime), but still, be careful with it especially if it is in a product for daytime use.
We don't have description for this ingredient yet.
We don't have description for this ingredient yet.
We don't have description for this ingredient yet.
The essential oil coming from the rind of the lemon that we make (or should make) lemonade from. In general, there are two problems with citrus peel oils: first, they are essentially the fragrant component, limonene in disguise (they are about 85-98% limonene).
Second, they contain the problematic compounds called furanocoumarins that make them mildly phototoxic. Lemon peel contains a medium amount of them, more than sweet orange but less than bergamot. Be careful with it especially if it is in a product for daytime use.
The essential oil created by steam distilling the leaves of the Eucalyptus tree. It's a colorless, pale yellow oil with a camphoraceous aroma used traditionally in vapor rubs to treat coughs. Its name-giving main component is eucalyptol (also called 1,8-cineole, 80-91%) that has significant antibacterial and expectorant properties.
Among essential oils, Eucalyptus Globulus counts as rather non-sensitising with an EU sensitizer total of 5% (due to limonene). However, if your skin is super-sensitive or you are allergic to fragrances, it is still better to avoid it.
The essential oil coming from the leafs of the lovely herb, rosemary. It contains several fragrant components, including the well-known irritant, camphor (around 15%). It has a nice smell, is a potent antioxidant and it's also an antimicrobial agent.
If your skin is sensitive, it's probably a good idea to avoid it.
We don't have description for this ingredient yet.
We don't have description for this ingredient yet.
Sweet, exotic and floral, it’ no surprise that Ylang Ylang is a popular essential oil. It is coming from the yellow, fragrant flowers of the Cananga tree native to tropical Asia and, similar to other essential oils, it is a chemically complex mixture with several pros and cons.
Unfortunately, these are a bit tricky to pin down as the composition varies largely depending on where it is sourced, how the oil is extracted and the grade of it that is used in the product, but we’ll do our best!
Let’s start with the easy stuff. The main components are fragrant molecules, including super common linalool (1-19%), benzyl benzoate (2-10%) and several others adding up to a max amount of 37.6% of EU sensitizers. The most expensive Extra grade is the most fragrant (has more benzyl acetate and cresyl methyl ether) and is used in high-end perfumes, while the First and Second grades are less fragrant, and used mainly in cosmetics.
Other than smelling nice and making cosmetic formulas also smell nice, Ylang Ylang might have some antimicrobial and antioxidant benefits and also works as an insect repellent. Its nice smell is also commonly known as being relaxing and calming (also backed up by a few recent studies), but it is an aromatherapy use case (when inhaled) so this probably does not count much skincare-wise.
On the other hand, the nice smell also means allergen fragrant components and 37.6% of EU sensitizers counts as quite high and the oil is considered to have high skin sensitization potential. It is a good idea to avoid if your skin is sensitive.
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| what‑it‑does | emollient | solvent |
| what‑it‑does | emollient |
| irritancy, com. | 0, 1 |
| what‑it‑does | emollient |
| what‑it‑does | emollient | moisturizer/humectant |
| what‑it‑does | emollient |
| what‑it‑does | skin-identical ingredient |
| what‑it‑does | emollient |
| what‑it‑does | emollient |
| irritancy, com. | 0, 0-2 |
| what‑it‑does | emollient |
| what‑it‑does | soothing | emollient |
| irritancy, com. | 2, 3 |
| what‑it‑does | emollient |
| irritancy, com. | 0, 1-3 |
| what‑it‑does | antioxidant |
| what‑it‑does | antioxidant | emollient |
| irritancy, com. | 0, 0-2 |
| what‑it‑does | emollient |
| what‑it‑does | soothing | emollient |
| what‑it‑does | soothing | emollient |
| what‑it‑does | emollient |
| what‑it‑does | antioxidant |
| irritancy, com. | 0-3, 0-3 |
| what‑it‑does | cell-communicating ingredient |
| irritancy, com. | 1-3, 1-3 |
| what‑it‑does | antioxidant |
| what‑it‑does | antioxidant |
| irritancy, com. | 0, 2 |
| what‑it‑does | antioxidant | skin brightening | buffering |
| what‑it‑does | emollient | perfuming |
| what‑it‑does | emollient |
| irritancy, com. | 2, 3 |
| what‑it‑does | moisturizer/humectant | solvent |
| what‑it‑does | emollient |
| what‑it‑does | emollient |
| what‑it‑does | emollient |
| what‑it‑does | emollient |
| what‑it‑does | buffering |
| what‑it‑does | antimicrobial/antibacterial | perfuming |
| what‑it‑does | perfuming |
| what‑it‑does | emollient |
| what‑it‑does | perfuming |
| what‑it‑does | perfuming |
| what‑it‑does | perfuming |
| what‑it‑does | perfuming |
| what‑it‑does | perfuming | antimicrobial/antibacterial |
| what‑it‑does | antioxidant | antimicrobial/antibacterial |
| what‑it‑does | perfuming |
| what‑it‑does | perfuming |
| what‑it‑does | perfuming |