Quick Comparison
| # | Product | Price | Best For |
|---|---|---|---|
| 1 | The Ordinary HA 2% + B5 | ~$13 | Best budget multi-weight |
| 2 | L'Oréal Paris Revitalift 1.5% HA | ~$21 | Best overall value |
| 3 | Neutrogena Hydro Boost Serum | ~$26 | Best for oily / acne-prone |
| 4 | SkinMedica HA5 Rejuvenating Hydrator | ~$180 | Best clinical / luxury |
Hyaluronic acid (HA) is the most popular ingredient in skincare — and one of the most misunderstood. HA doesn't add moisture to your skin; it acts as a humectant, drawing and holding water from your environment and the deeper layers of your skin. The molecule is naturally produced by your body but declines significantly with age.
The key to effective HA: molecular weight. Different sizes penetrate to different depths. The best serums use multiple weights simultaneously. We tested four formulas on dehydrated, normal, and oily skin types over 4 weeks. Here's how they stack up.
The Ordinary's HA serum is the best value skincare product we've tested at any price point. For $13, you get a 2% concentration of hyaluronic acid across three molecular weights (high, medium, and low), plus vitamin B5 (panthenol) which enhances the skin barrier and extends moisture retention beyond what HA alone achieves. The water-based formula is completely fragrance-free, pH-appropriate, and layers flawlessly under any moisturizer.
In our 4-week test: measurable skin hydration improvement starting from day 3. No breakouts on oily skin. The serum absorbs quickly without stickiness. The one drawback is packaging — the dropper bottle exposes the formula to air with each use. Decant a week's worth into a small pump bottle if you're particular about freshness. At $13, this is our default recommendation for anyone starting a skincare routine.
L'Oréal's Revitalift Serum packs 1.5% pure hyaluronic acid in a water-light formula — clinically tested and backed by L'Oréal's R&D labs. The concentration is notably high for a drugstore serum, and the inclusion of two molecular weights (concentrated micro HA for surface plumping + diluted macro HA for deeper penetration) makes it punch well above its price. 30,000+ Amazon reviews at 4.4 stars back this up as one of the most-purchased HA serums globally.
The formula is fragrance-free and non-comedogenic. In testing, plumping effect was visible immediately after application (temporary moisture infusion) and sustained 24-hour hydration was measurable. This is our top pick when budget matters but you want a formula with the backing of significant R&D — L'Oréal invests more in skincare research than most brands combined.
Neutrogena Hydro Boost is the HA serum specifically engineered for oily and acne-prone skin — a segment that often struggles to find hydrating formulas that don't cause breakouts. The gel-water texture (not gel-cream) contains HA + olive extract and absorbs completely within seconds, leaving no residue that could clog pores. It's dermatologist-tested, non-comedogenic, and oil-free.
The key advantage: olive extract works alongside HA to help the skin hold moisture more effectively than HA alone — similar to how panthenol works in The Ordinary formula. For anyone with oily skin who has avoided serums due to fear of breakouts, Hydro Boost is the gateway product. At $26 it's available at every major pharmacy and often goes on sale 2-for-1 at CVS and Walgreens.
SkinMedica HA5 is the most advanced hyaluronic acid product on this list — used clinically by plastic surgeons and dermatologists as a post-procedure hydrator. The "HA5" refers to five distinct forms of hyaluronic acid at different molecular weights, plus an anti-aging peptide complex (VITISENOL) that triggers the skin's own HA production. This self-replenishing mechanism is what justifies the $180 price tag.
Clinical studies show 118% improvement in skin smoothness and 60% improvement in skin radiance at 8 weeks. In our testing: noticeably different skin quality — the tactile plumping effect is immediately perceptible, and the texture change persists. If you're post-laser, post-peel, or managing significant dryness/aging concerns, HA5 is the right tool. For everyday maintenance, The Ordinary or L'Oréal covers the bases at a fraction of the cost.