Any recommendations for dark circles under the eyes?

[Mitochondria7]

Products to use that effectively work

[WinglessOne]

@Mitochondria7  It depends on what’s causing your dark circles. 

Sun damage: Look for products containing retinol, kojic acid, vitamin C, or arbutin—and make sure they’re safe to use under your eyes.  

Spoiler

Some of my undereye darkness was caused by sun damage, and Dr. Dennis Gross Skincare Ferulic + Retinol Triple Correction Eye Serum knocked it out within 3 months. Your mileage may vary, of course, and there might be another product that’d work better for you. 

If you already use a vitamin C serum on your face, apply a thin layer under your eyes too—but don't bring it all the way up to your lash line, lest you accidentally get it in your eye. Same goes for serums containing the other ingredients I mentioned, though DDG says their eye serum is safe all around the eye, including eyelids. 

I've never used The Ordinary Alpha Arbutin 2% + HA Hyperpigmentation Serum 1 oz/ 30 mL , but I like the look of its ingredients list. 

Allergies (sinus pressure, inflammation, and/or frequent eye rubbing): Good ol’ antihistamines can help, which you’d likely be taking anyway for allergy symptoms. Cold compresses also help me a lot here. So do serums and refrigerated eye patches that contain anti-inflammatory ingredients like green tea, licorice root, and centella asiatica. 

Spoiler

My favorite eye patches are JayJun Green Tea Eye Gel Patch. They always sooth the heck outta my undereyes. I usually keep a jar in the fridge. You could also try SEPHORA COLLECTION Eye Mask - Cucumber - Anti-Puffiness Cucumber or SEPHORA COLLECTION Clean Eye Mask Cucumber . And many people love Skyn Iceland Hydro Cool Firming Eye Gels. 

My skin's favorite anti-inflammation serums are COSRX Purefit Cica Serum (features centella asiatica, aka cica) and It's Skin Power 10 Formula LI Effector (features licorice root). Both of those serums also contain a good amount of hyaluronic acid, a great humectant. Whether those serums will work for you depends on what your particular skin responds best to. 

Lack of sleep: Products containing caffeine can possibly help. You can also try plumping the skin a bit with products containing hydrating/moisturizing ingredients like hyaluronic acid, glycerin, ceramides, squalane, rosehip oil, avocado oil, etc. You don’t need to use something specifically marketed as “eye cream”; a full face moisturizer or a facial oil can work fine under your eyes. 

Spoiler

There are a couple of eye patches I can think of that contain caffeine: Peace Out Puffy Under-Eye Patches and SEPHORA COLLECTION Clean Eye Mask Caffeine . There's also The INKEY List Caffeine De-puffing + Dark Circle Eye Cream 0.5 oz/ 15 mL which some folks like. (I've never used it.) 

There are so many options for skin-plumping hydrators/moisturizers! A good option that can also work for your whole face is the tried and true CeraVe Moisturizing Cream, which (like all CeraVe products) is loaded with ceramides. 2 of my usual full face moisturizers that work great under my eyes are Youth To The People Superfood Air-Whip Lightweight Face Moisturizer with Hyaluronic Acid 2 oz / 59 mL and The INKEY List Vitamin B, C, and E Moisturizer 1.7 oz/ 50 mL . Also, whenever I apply a serum that contains lots of hyaluronic acid to my whole face, I make sure to include my undereyes. Some serum options are The Ordinary "Buffet" 1 oz/ 30 mL , Farmacy Very Cherry Bright 15% Clean Vitamin C Serum with Acerola Cherry 1.0 oz/ 30 mL (my current usual vitamin C serum), The INKEY List Hyaluronic Acid (HA) Hydrating Face Serum 1 oz/ 30 mL , Drunk Elephant B-Hydra™ Intensive Hydration Serum with Hyaluronic Acid 1.69 oz/ 50 mL , First Aid Beauty Ultra Repair® Hydrating Serum , and countless others. 

If you want to layer a facial oil with your full face moisturizer under your eyes, some good options are The Ordinary 100% Organic Cold-Pressed Rose Hip Seed Oil 1 oz/ 30 mL , e.l.f. Nourishing Facial Oil, The Ordinary 100% Plant-Derived Hemi-Squalane , Biossance 100% Sugarcane Squalane Oil 3.4 oz / 100 mL , Herbivore Emerald CBD + Adaptogens Deep Moisture Glow Oil 1 oz/ 30 mL , and many others. 

Sunken skin (hollow tear troughs): Plumping up the sunken skin can reduce these dark circles. Injectable fillers like Restylane or Juvaderm provide the best and fastest results, though they’re temporary. You can also try a topical hydrating/moisturizing product to plump the skin, but it won’t give you anywhere near an injectable’s results. Concealer can also work wonders here. 

Spoiler

I still have this kind of undereye darkness. I’m not willing to go the injectables route yet, so I rely on hydration/moisturization and concealer/color corrector in my tear troughs. I often apply a tiny bit of a color correcting shade of concealer (for me, that's usually BECCA Cosmetics Ultimate Coverage Longwear Concealer Cinnamon ) or a shade very close to my natural skin tone (for me, that's NARS Radiant Creamy Concealer Amande ) just in my tear troughs. Then I apply an even smaller bit of a lighter shade of concealer right in the hollow (I've been using PAT McGRATH LABS Sublime Perfection Concealer MD23 or a couple other shades for this; I'm experimenting to figure out my best PMG shade) and very carefully blend it out, keeping it off the raised skin around my hollow tear troughs. This technique creates an optical illusion that kinda lifts the hollow skin up, making it appear brighter and less sunken. 

Or, sometimes I apply my usual concealer shade and then use a tiny bit of highlighter in my tear trough to bounce light off those shadows. 

Your genes (hereditary dark circles): You could try products that target hyperpigmentation but honestly, color correction products and/or concealers are your best bet.