popular cosmetic ingredients via Google
There are a number of cosmetic + personal care ingredients that are used to create a product. As an introduction, I'll be going over some popular cosmetic ingredients -- based on a simple Google search "popular cosmetic ingredients". A lot of the information below is information that I've gathered through my own experience, but please feel free to browse the links at the end of the post.
Parabens
Parabens are based on parahydroxybenzoic acid. The R group in the chemical structure is what determines what the paraben is (ex: methylparaben, ethylparaben).
They show strong antimicrobial properties & have been used in many products & industries (cosmetic, pharmaceutical, food, & industrial) as preservatives. Parabens are effective against Gram+ and Gram- bacteria, yeast, and mold at relatively low concentrations. They're cheap and compatible with many types of products.
There have been some concerns about how parabens affect people's health or how it can cause cancer. Parabens have been studied extensively for decades now and have been deemed safe for us (within a particular percentage, of course). You can read the CIR’s safety assessment of Parabens in cosmetics here. You can also read the CDC’s paraben factsheet here.
"Paraben-free" is a “free-from” marketing ploy developed from the paraben-scare that parabens were linked to cancer. Studies have shown its safety and unless you're actually allergic or sensitive to parabens, I think that it would be fine for continued use in products.
Of course, to each their own. However, in my opinion, you should not be concerned about using products that contain parabens (so long as they are being used at proper levels). I would be more concerned about using products that do not have any preservatives in it rather than having parabens.
One of my favorite products that just so happen to contain parabens:
CeraVe Moisturizing Cream for Normal to Dry Skin ($13.99 for a 12 oz)
Hyaluronic Acid
Hyaluronic acid is a polysaccharide that is naturally occurring in our bodies and our skin. Due to its polar nature, it can hold onto water efficiently. Hyaluronic Acid is extremely hygroscopic, meaning that it has a tendency to absorb moisture from the air. It can bind up to 1000x its weight in water -- hydration power at its finest, making it a cult-favorite!
Hyaluronic acid in your skin decreases with age and may contribute to the development of fine lines, wrinkles, and other signs of aging. Some fillers used in dermatology or plastic surgery uses hyaluronic acid solution injections.
In cosmetics, hyaluronic acid can be offered in different sizes -- high and low molecular weights. High molecular weight hyaluronic acid moisturizes skin and forms viscous solutions. Low molecular weight hyaluronic acid can increase skin elasticity and reduce fine lines and wrinkles -- it's believed to have better skin penetration because its lower in molecular weight.
You may also see Sodium Hyaluronate in place of hyaluronic acid.
Sodium hyaluronate is the sodium salt form of hyaluronic acid and it typically has a lower molecular weight. Again, it is thought to have better skin penetration because of its lower molecular weight with the same moisturizing and water binding capabilities.
My favorite Hyaluronic Acid / Sodium Hyaluronate containing products:
The Ordinary Hyaluronic Acid 2% + B5 ($6.80 for 30 mL)
Glow Recipe Watermelon Pink Juice Moisturizer ($39.00 for 2 oz)
Retinol
Retinol is Vitamin A and has been used in skincare to target many concerns, such as:
pigmentation
wrinkles
acne-prone skin and more
The major dietary sources of retinoids are plant carotenoids (e.g. carrots) and retinol esters derived from animal derived foods. Retinol is a storage form of vitamin A that can be converted to retinal which is important for eye health -- this is why people say that carrots are good for your eyes (but it is also see that it is good for our skin).
There are many forms of vitamin A used in the market -- retinol, retinyl palmitate, hydroxypinacoloneretinoate, retinyl retinoate, retinal, etc. These different forms of vitamin A have various claims in irritation, photo and heat stability, and efficacy.
It is important to use SPF when you are using a product with retinol or vitamin A because of light sensitivity. Retinol products should generally be used at night to prevent further irritation from the sun.
In lieu of retinol, here are a few different retinoid containing products that I like:
The Ordinary Granactive Retinoid 2% in Squalane ($9.60 for 30 mL) - The Ordinary offers Retinol in Squalane & also offers it in a stronger dose (%). I specifically like the one that I list here because I do not experience dry, flaky skin with use.
Differin Gel Adapalene Gel 0.1% Acne Treatment (various price + sizes) - This contains the retinoid adapalene, the first over-the-counter active ingredient for acne.
Titanium Dioxide
Titanium dioxide is typically used in sunscreens, makeup & cosmetics. In makeup & cosmetics, it is typically the “white” color that can be used to create different shades. It can also act as a UVB absorber, what most relate to being a “physical” sunscreen.
You will also see titanium dioxide on the California Prop 65 list, but the main thing to point out is that it lists AIRBORNE, UNBOUND particles of respirable sized titanium dioxide. When in an emulsion or even a gelled product, titanium dioxide can be considered bound.
Zinc Oxide
Zinc oxide is another “physical” sunscreen and acts as a UVA absorber. In combination with titanium dioxide, you'll then have protection against UVA & UVB rays. However, it may be necessary to use SPF boosters when formulating with either metal oxide to boost efficacy.
Metal oxides used as physical sunscreens may leave a white cast during use & so formulating with them may be a little more difficult if you wish to give better aesthetics to your product.
Nonetheless, titanium and zinc oxide are great “physical” sunscreens. It is important for you to use SPF everyday & reapply regularly! I highly recommend to use a sunscreen of at least SPF 30!
If a product makes any SPF-claims, you will be able to see the "Active Ingredients" on the label, & you will also see at what % of the ingredient is used.