15 best-selling beauty products you probably didn’t know were at Costco

If you've noticed your hair is looking a little lackluster lately, Pura d'or's Advanced Therapy shampoo for thinning hair is a great choice. In fact, we've dubbed the brand's biotin shampoo as our pick for the best all-natural hair thinning shampoo in our guide to the best shampoos for thinning hair. 

The Advanced Therapy shampoo and conditioner set is designed specifically to reduce hair thinning due to breakage, whether that's because of dry hair, over bleaching, excessive damage and more. The formula is made with a blend of vitamins and botanical extracts including pumpkin seed oil, nettle and black cumin seed oil, all of which are shown to nourish hair follicles and prevent split ends and breakage. 

Who doesn't want hydrated, younger-looking eyes? This hyaluronic under-eye cream from powerhouse brand StriVectin is the hero your bathroom cabinet is missing. The swirled gel-like formula intensely hydrates and moisturizes the delicate skin of under eyes, while battling the signs of aging like fine lines, wrinkles, crow's feet and puffiness. 

Whether you're a devout user of La Mer's Moisturizing Cream or you've been curious what the hype is about, we can't deny we were surprised to see this top-tier, cult-famous, richy-rich face cream at Costco, of all place.

La Mer's ultra-rich and hydrating face cream unlocks younger, healthier, more vibrant-looking skin in just a few uses. The brand is famous for its secret formula — which they've dubbed the "Miracle Broth" — and a main ingredient different from most skin care products out there: algae extract. 

Please note that this is a member-only product at Costco.

Master the no-makeup makeup look with this barely there mascara. It's both a mascara and a lash treatment and is designed to create the appearance of more lifted longer, thicker lashes while hydrating strands with every swipe. The application comb includes different bristles on each side — wide and flexible, fine and firm — so you can get exactly the look you want. 

Discover the secret to Cleopatra's skin care secret with this all-in-one skin care set. "Based on the ancient Egyptian formula that Cleopatra used to keep her skin healthy and glowing, Egyptian Magic Skin Cream has become beauty’s most magical secret," according to the brand. 

If you're no-fuss about your skin care routine and want one product that can do it all, this might be the product for you. Use it as a moisturizer, lip balm, eye cream, cuticle and hand moisturizer, hair and face mask and even as a make-up primer. Use a swipe on eye elbows, rough enough and dry feet as well. It's an all-in-one product that deserves space in your bathroom cabinet.

Made of natural ingredients like shea butter, aloe vera, beeswax and soy proteins, Embryolisse Lait-Creme face and body cream is a great choice for those who are sensitive to ingredients. It's a bit of an all-use product: smooth it all over after a shower, swipe it onto dry skin, use it after shaving, and hydrate your skin after sun exposure. You'll end up with skin that's firm, smooth, soft and supple. 

Achieve longer, fuller, healthier-looking lashes with each swipe of this lash-enhancing serum. This serum is made with ingredients like polypeptides, biotin, amino acids and hydrating oils and extracts that, when used daily, will strength each strand against breakage — and will lead to more youthful-looking lashes. You can also apply it to brows to encourage thicker, fuller brows. 

A good lighted makeup mirror is essential in the mornings, especially in the winter when it's dark and dreary outside. This bestseller from Simplehuman has both 5x and 10x magnification, which can be useful for putting in contacts, plucking eyebrows, putting on lipstick and much more. 

We especially love that it automatically lights up when you approach it, and the light it designed to simulate natural sunlight. It's core-free and rechargeable so you don't have to worry about tripping on an unsightly cord. Choose from silver or rose gold. 

Please note that this is a member-only product at Costco.

Improve your skin from the inside out with a daily dose of collagen powder. This grass-fed collagen powder delivers 8 grams of high quality collagen per scoop to reduce wrinkles and helps strengthen hair, skin, nails, bones and joints over time. Collagen can also help thicken hair as well as promote firmer, softer skin. While it is unflavored, most reviewers recommend blending it into smoothies, juices or dissolving it into morning coffee with milk or cream. 

Cleanse, exfoliate and hydrate your own skin without having to get a facial thanks to this resurfacing face scrub. Made of exfoliating walnut shell powder, calming chamomile and anti-bacterial willow bark, this unique formula can be used on even the most sensitive skin types. The fine-ground formula is ideal for removing blackheads and deep-cleaning acne-prone skin. It's recommended to use two to three times a week.

If you frequently forget about sunscreen, reach for this brush-on sunscreen instead. It's innovative powdered sunscreen protects against UVA and UVB damage while remaining waterproof and reef-safe. Wear it alone or with makeup. The small self-dispensing brush is small enough to keep in your purse or makeup bag, so that you can swipe it on at the end of your makeup routine. It's also easy for men and kiddos to use, too. 

Stop hair loss and protect your strands at the source with this stimulating anti-hair loss shampoo. It's made without ingredients that can damage hair growth like sodium lauryl sulfate, parabens and Phthalates. Instead, it's made with energizing ingredients that have been shown to promote healthier, thicker hair such as copper peptides, biotin and caffeine. It does, however, contain emu oil, so vegetarians and vegans might reach for another shampoo instead.

For optimal results, lather and leave it on hair for two minutes before rinsing away — the longer the ingredients have time on your strands and scalp, the better.

Unlock dewy, hydrated, younger-looking skin with this non-greasy serum that's designed to boost your skin's natural glow. Though technically a serum, it dries to a non-sticky, matte finish that'll leave you feeling supple and hydrated without needing to layer on thick lotions and creams. 

Reduce the appearance of stretch marks, retain collage and improve skin's elasticity with this rich and creamy moisturizing concentrate. Use in the morning and evening on the face to treat wrinkles and fine lines, or use on stretch marks twice a day to improve their appearance over time. 

Facial essences are extremely common in Japanese and Korean skin care routines, but are still somewhat unfamiliar to some western shoppers. Essences are used kind of like an extra layer of hydration on the skin, and should be used after cleansing the skin and before putting on serums and moisturizers.

And the queen of essences? That would be SK-II's Treatment Essence, which is formulated with the brand's very own special ingredient called "PITERA" — which appears to be an organic by-product derived from the sake fermentation process. The essence is designed to be a hero product for your beauty cabinet, taking on the task of hydrating, moisturizing, softening and smoothing texture all in one.

Please note that this is a member-only product at Costco.