What's inside
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Hyaluronic acid (HA) is a glycosaminoglycan (basically a long sugar chain) that your skin already makes on its own. In your skin, HA lives in the extracellular matrix and acts as the body's moisture reservoir.
Topically, HA is a humectant that binds water and helps skin look more plump, smooth, and hydrated.
The only catch is that HA isn't a single thing; it actually comes in a wide range of molecular weights (~50 - 2,000+ kDA) and size matters.
Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.
This is why the best HA serums blend the two sizes together so you get the best of both worlds.
The majority of cosmetic HA is produced by bacterial fermentation, typically using Streptococcus or Bacillus strains. Typical use levels in skincare sit around 0.1-2%.
A clinical study using a 0.2% low-molecular weight HA gel showed improvement in facial seborrheic dermatitis with excellent tolerance.
These are some other common types of Hyaluronic Acid:
Learn more about Hyaluronic AcidTretinoin (aka retinoic acid) is the gold standard retinoid in dermatology because it's the form of vitamin A that your skin can use right away. It's a prescription drug and regulated as medication in most countries.
Unlike retinol, it skips the conversion steps and goes straight to work.
Inside your skin cells, it binds to receptors called retinoic acid receptors and switches on the genes that control how skin cells behave.
For acne, it helps your skin shed dead cells properly instead of letting them build up and clog your pores (this is what turns into blackheads and pimples). It also calms redness/swelling, which is why it's a FDA-approved acne treatment.
Tretinoin also tells your skin to make more collagen and slows down the stuff that breaks collagen apart too. Over time, your skin looks smoother, softer, and more even, with fewer lines lines and sun spots.
The evidence for this ingredient is strong:
A systematic review of randomized controlled trials found that topical tretinoin consistently improved wrinkles, pigmentation, sallowness, and dark spots. Results typically showed up as early as one month and lasted out to 24 months.
All studies also found this ingredient to be safe and well-tolerated.
Typical concentrations run from about 0.01-0.1%, with 0.025%-0.1% being the usual range studied for photoaging and a 0.05% cream producing measurable wrinkle/roughness improvements in large six-month trials.
The main trade-off is irritation; dryness, peeling, redness, and sun sensitivity are common in the first few weeks so be sure to pair it well with a good moisturizer and daily sunscreen.
Learn about a form of retinoid you can purchase at the store, retinol.
Learn more about Tretinoin
