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Six dollars. That's what Good Molecules charges for their Niacinamide Serum. Not six dollars per ounce, not six dollars on sale with a coupon code — six dollars for a full 30ml bottle. When I first saw the price, I assumed it had to be a stripped-down formula with a token amount of niacinamide and a whole lot of filler. I was wrong. This is a 10% niacinamide serum in a thoughtfully formulated base that genuinely competes with products three and four times its price. After two weeks of daily wear testing, I'm still trying to figure out how they pulled this off.

Full disclosure: I went into this test skeptical. I've been burned by cheap skincare before — thin textures, weird smells, serums that pilled under everything and left my face feeling like I'd spread aloe gel over it. The bar was low. But Good Molecules cleared it easily, and then some.

Brand Context: Good Molecules' Mission

Good Molecules is a US-based skincare brand that launched with a clear mission: make effective, ingredient-focused skincare that doesn't cost a fortune. They're part of the same wave as The Ordinary and The Inkey List — brands that stripped away the marketing fluff and luxury packaging to deliver straightforward formulas at honest prices. But Good Molecules differentiates itself in a few key ways. Their formulas tend to be more elegant than The Ordinary's (which can feel like chemistry experiments), and they're more transparent about sourcing and ingredient quality than most budget brands.

The Niacinamide Serum is one of their core products, and it sits alongside their Discoloration Correcting Serum and Silicone-Free Daily Moisturizer as the products that built their reputation. The brand is widely available through Ulta, Amazon, and their own website, which makes it easy to find — something that can't be said for every budget skincare brand.

Ingredient Breakdown: A Lean, Focused Formula

The full INCI list is refreshingly short: Water, Niacinamide, Dipropylene Glycol, Glycerin, 1,2-Hexanediol, Betaine, Tocopherol, Hydrogenated Lecithin, Xanthan Gum, Sorbitan Isostearate, Diphenyl Dimethicone, Triethylhexanoin, Polyglyceryl-10 Oleate, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Ethylhexylglycerin, Polysorbate 60.

Niacinamide at 10% is the star of the show. This concentration sits right in the sweet spot for niacinamide efficacy — high enough to deliver visible results on pore appearance, sebum regulation, and hyperpigmentation, but not so high that it causes irritation. The 5% threshold is where niacinamide starts showing measurable effects on barrier function and melanin production, and 10% is the most commonly studied concentration for sebum reduction. INCIDecoder rates niacinamide as a "superstar" ingredient, and it's earned that designation through decades of clinical research. It's a cell-communicating ingredient that signals skin cells to produce more ceramides and less melanin, while also reducing inflammation and improving barrier function.

Glycerin and Dipropylene Glycol form the humectant backbone. Glycerin is the gold standard of humectants — it draws moisture into the skin and creates a protective hydration layer. Dipropylene Glycol serves a dual purpose: it's a humectant that also improves the texture and spreadability of the serum. Together, they prevent the drying effect that some high-concentration niacinamide serums can cause.

Betaine is an amino acid derivative that functions as a humectant and skin-conditioning agent. It's a gentle ingredient that helps maintain skin hydration without stickiness, and it's classified as a "goodie" by INCIDecoder. Betaine is increasingly common in K-beauty formulations for its ability to improve skin feel without adding weight.

Tocopherol (Vitamin E) is the antioxidant in this formula. It protects the skin from free radical damage and also helps stabilize the other ingredients. INCIDecoder rates it as a "superstar" — it's one of the most well-researched antioxidants in skincare, and it pairs well with niacinamide because both support barrier function through different mechanisms.

Hydrogenated Lecithin is a phospholipid that serves as both an emollient and a penetration enhancer. It helps the niacinamide penetrate deeper into the skin rather than sitting on the surface. It's also a "goodie" ingredient that supports the skin's natural lipid barrier.

1,2-Hexanediol and Ethylhexylglycerin are the preservative system. 1,2-Hexanediol is a gentle preservative that also functions as a humectant, and Ethylhexylglycerin is a deodorizing preservative booster. This is a common preservative pairing in K-beauty formulations, and it's generally well-tolerated by sensitive skin.

What's notably absent from this formula: fragrance, essential oils, and denatured alcohol. There's no zinc PCA (unlike The Ordinary's 10% + Zinc), which means this serum won't have the same astringent, oil-controlling effect. But the trade-off is a gentler, more hydrating formula that's less likely to cause dryness or irritation.

Texture & Application: The Lightweight Champion

Here's where Good Molecules genuinely surprised me. The texture is a lightweight, slightly viscous liquid that spreads easily and absorbs within about 30 seconds. It's not as thin as water — it has enough body to sit on the skin briefly before sinking in — but it's far from the thick, sticky gel that The Ordinary's niacinamide serum is known for. The closest comparison I can make is to a very lightweight essence.

On application, there's a brief moment of tackiness that dissipates as the serum absorbs. By the time I'm reaching for my moisturizer, the tackiness is gone. No pilling, no residue, no white cast. It layers beautifully under sunscreen, under moisturizer, and under other serums. I tested it in the morning routine after cleansing and toning, and in the evening after a double cleanse. In both positions, it played well with everything.

The dropper is standard — nothing fancy, but functional. The bottle is clear glass with a minimalist label, which looks clean on a shelf but means you need to keep it away from direct sunlight. Niacinamide is relatively stable, but clear packaging is never ideal for any active ingredient. A tinted bottle would have been a nice touch at this price point, but it's hard to complain when the formula itself is this solid.

Two-Week Wear Test: Day by Day

Days 1-3: I applied three drops each morning and evening after cleansing and toning. The serum absorbed quickly and layered well under my sunscreen (Biore UV Aqua Rich Watery Essence) in the morning and under my moisturizer (Illiyoon Ceramide Ato Concentrate) at night. No irritation, no stinging, no breakouts. My skin felt hydrated but not sticky — a good sign for a niacinamide serum.

Days 4-7: By the end of the first week, I noticed my skin looked slightly less oily by midday. This is the classic niacinamide effect — sebum regulation takes about a week to become visible. I also noticed that my pores around my nose and cheeks looked slightly less pronounced. Not dramatically different, but enough that I noticed it in my morning mirror check. No new breakouts, no irritation.

Days 8-10: I hit a rough patch around day 9 — I had a small breakout on my chin that I attributed to hormonal cycling rather than the serum, since it was localized and the rest of my face was clear. The breakout resolved within two days, which is faster than usual for me. Whether that's the niacinamide's anti-inflammatory effect or just coincidence, I can't say for certain. But the timing was encouraging.

Days 11-14: By the end of the two-week test, my skin was consistently less oily throughout the day, my pores looked marginally smaller (especially around my nose), and my overall skin texture was smoother. The redness around my cheeks was slightly reduced — not dramatically, but enough to notice. My skin felt well-hydrated and balanced, and the serum had become a seamless part of my routine that I didn't have to think about.

The key takeaway from the wear test: this is a niacinamide serum that does exactly what it should, without drama. It's not going to transform your skin overnight, but it delivers consistent, visible results over two weeks. The bar for a good niacinamide serum isn't that it performs miracles — it's that it works reliably and doesn't cause problems. Good Molecules clears that bar comfortably.

Pros

Cons

Who Is This For?

This serum is ideal for anyone who wants a no-frills, effective niacinamide serum at a price that doesn't hurt. It's especially well-suited for oily and combination skin types who want sebum regulation and pore refinement without the drying effect of zinc-based formulas. Sensitive skin types will appreciate the lack of fragrance and essential oils, though you should always patch test with any new active.

If you're new to niacinamide and want to try it without committing $15-25, this is the perfect entry point. If you're an experienced niacinamide user looking for a reliable daily driver that won't break the bank, this fills that role too. The only people who might want to look elsewhere are those specifically seeking a niacinamide + zinc combination, or those who want a more innovative formula with additional actives.

Price & Where to Buy

$6.00 USD for 30ml. Available at:

At $6 for 30ml, this comes out to roughly $0.20 per ml — making it one of the most affordable niacinamide serums on the market. For comparison, The Ordinary's 10% + Zinc 1% runs about $6.70 for 30ml, and Naturium's 12% + Zinc 2% is around $17 for 30ml. The Good Molecules formula is genuinely competitive on a per-ml basis, and it's often cheaper when Ulta runs their frequent sales.

Comparison Notes

The Ordinary Niacinamide 10% + Zinc 1%: The most direct comparison. The Ordinary's formula is similarly priced ($6.70) but includes zinc PCA for additional oil control. The trade-off is texture — The Ordinary's serum is noticeably thicker and stickier, with a gel-like consistency that takes longer to absorb and can pill under certain sunscreens. Good Molecules wins on texture and layering; The Ordinary wins if you specifically want the zinc. Both are effective at 10% niacinamide.

Naturium Niacinamide Serum 12% Plus Zinc 2%: At $17 for 30ml, Naturium costs nearly three times as much but delivers a higher niacinamide concentration (12% vs. 10%) and a more sophisticated formula with zinc PCA, sodium hyaluronate, and vitamin E. The texture is more elegant than The Ordinary's, similar to Good Molecules in lightness. If budget isn't a concern, Naturium is the more complete formula. But if you're comparing value per dollar, Good Molecules is hard to beat.

COSRX The Niacinamide 15%: A K-beauty option at a higher concentration (15%) with a slightly higher price point ($12-15). COSRX's formula includes zinc PCA and is designed for more severe pore and oil concerns. The higher concentration means more potential for irritation, especially for sensitive skin. Good Molecules is the gentler, more accessible option; COSRX is the stronger choice for those who need it.

Final Verdict

The Good Molecules Niacinamide Serum is exactly what a budget skincare product should be: a straightforward, effective formula that delivers real results without asking you to compromise on texture, ingredient quality, or experience. It's not the most exciting serum on the market, and it's not going to revolutionize your routine. But it's a reliable, well-formulated niacinamide serum at a price that's genuinely hard to argue with.

After two weeks of testing, I can confidently say this belongs in the "best value" conversation for niacinamide serums. The lightweight texture is a genuine improvement over The Ordinary's sticky formula, the 10% concentration is well-supported by research, and the clean INCI list is free of common irritants. The lack of zinc is a trade-off, not a flaw — it makes this a gentler, more hydrating option that's better suited for sensitive and combination skin.

If you're looking for a niacinamide serum and don't want to spend more than $10, stop looking. This is it.