It can be really hard to ascertain whether our skin-care routine is actually working or not. Treating glaring issues like dryness or an angry zit is one thing. But the day-to-day maintenance with long-tail results, like brightness, firmness, and smoothness, can be difficult to gauge: Are those fine lines really going away? And does that serum really make you look dewier, or are you just standing in the right light?

So when a product that”does wonders for skin” and promises “results in a few days,” we take notice. Apparently, Glytone’s Age Defying Peptide+ Overnight Restorative Cream ($64) won’t make you question its effectiveness. Not only is it a product that actually delivers on its promises, but it’s also 20 percent off right now during the Glytone Flash Sale when you spend $65 or more, which—judging from the number of other highly-praised products—won’t be hard to do.

Glytone, Age-Defying Peptide+ Overnight Restorative Cream — $64.00

Originally $80, now $64

Key ingredients: tetrapeptide complex, albizia extract, hyaluronic acid

As for the Age Defying Peptide+ Overnight Restorative Cream, it’s formulated with glycolic acid (the hero ingredient behind all Glytone products) and hylauronic acid to firm and restore the look of skin overnight. It’s so effective that one shopper in her sixties swears by it for getting that lit-from-within look, so much so that she’s ditched her foundation and concealer for good. “I’ve been using Glytone products for over 30 years. I was introduced to it by my dermatologist. Without exaggeration, my skin, especially my cheeks, glow,” they write. “I’ve stopped using makeup base and always use sunscreen.”

Another shopper also in her sixties says it’s even gotten her compliments from her doctor: “Saw my dermatologist two weeks ago and she said my skin looked beautiful… Love all the Glytone products that I have purchased.”

It’s no surprise it works; The brand was founded by a trio of pharmacists and dermatologists who wanted to harness the power of acids for healthier, happier skin. All of its products are rooted in science and strategically crafted to give you noticeable, professional results—and it delivers. Snag this night cream and other Glytone goodies for 20 percent off when your spend $65 or more, now through March 29.

Save 20% off on more Glytone skin care below

Age-Defying C+ Advanced Antioxidant Serum — $74.00

Originally $92, now $74 

Key ingredients: antioxidant complex, THD ascorbate, squalane

The lightweight serum is part of the brand’s Age-Defying line and is formulated to tackle fine lines, age spots, and other signs of oxidative stress. As one shopper puts it, it’s “one of the best” they’ve ever used, leaving skin “hydrated and radiant all day.” That’s thanks to its hero ingredient, a potent antioxidant complex bursting with vitamin C, E, and squalane that leaves skin brighter while reversing signs of aging.  It’s also hydrating and, when paired with the matching cream, quenches skin with long-lasting moisture.

Lactic Superficial Retexturizing Serum — $56.00

Originally $70, now $56

Key ingredients: lactic acid, rosemary oil, tea tree oil

Looking to get that lit-from-within skin? Try this gentle peel, which one shopper dubs a “fountain of youth”: “Glytone lactic retexturizing serum and made my skin go back 10 years!” the same reviewer swoons. “My face looks youthful, glowing, and has helped smooth out rough patches I’ve had issues with around my chin and corners of my nose. My makeup glides on smooth and have received many compliments about my skin tone.”

The secret lies in the serum’s 10 percent lactic acid, which gently sloughs away dead skill cells to reveal lighter, clearer skin. There’s also hyaluronic acid as to not dry out skin, as well as rosemary and tea tree oils to soothe irritation.

Enhance Brightening Cleansing Powder — $40.00

Originally $50, now $40

Key ingredients: AHA complex, niacinamide, malic acid

This cleanser gets high praise for its brightening ingredients and its dry, powdery form alike. Unlike traditional washes, this powder-based cleanser activates in contact with water, turning the powder into a creamy, exfoliating paste to reveal more awake-looking skin. Its unique design makes it particularly travel-friendly, making worrying about spills and TSA liquid limits a thing of the past.

Age Defying PHA + Renewing Eye Cream — $65.00

Originally $79, now $69

Key ingredients: lactobionic acid, peptides, hyaluronic acid

Another treatment in the Age Defying line, this eye cream will send heavy, sleepy under-eye bags packing. Scroll through review after review of happy customers who swear by it for both firming and soothing the delicate areas around their eyes. “I was shocked by how well this eye cream works. I have tried so many different brands and formulas, but this is the first one that actually makes a significant difference,” one reviewer writes. “In two weeks, my fine lines are noticeably less visible, my dark circles are lighter, and underneath my eyes are less puffy. I noticed an improvement in all of these areas within five days, but the results got even better over time.”

Hydra Lipid UV Mineral Sunscreen SPF 40 — $30.00

Originally $36, now $30

Key ingredients: hyaluronic acid, squalane

Even though you should be wearing sunscreen all year long, spring is the perfect time to restock your SPF. Shoppers recommend this hydrating sunscreen which doubles as a daily moisturizer, quenching thirsty skin while protecting it from harmful UVA/UVB rays. It’s technically a mineral sunscreen, which means it uses zinc oxide and titanium dioxide to filter out UV. But it’s not chalky or heavy, like other mineral SPFs tend to be, and is instead infused with hyaluronic acid and squalane for a lightweight burst of hydration.

“One of the best sunscreens I have used” one reviewer writer. “It… leaves a beautiful soft glowing sheen without ever looking greasy! This did not irritate my sensitive skin. I highly recommend this!”