'I try hundreds of serums every year. You've probably never heard of the ones I repurchase.'

I've worked as a beauty writer for over a decade, which means my face has been the test subject for hundreds (maybe even thousands) of serums.

It's the beauty sub-category my friends, family and even random strangers in my DMs constantly ask me about.

There are so many serums out there, all promising to give you "glass skin" or a complete skin transformation.

And yet, half the time you're left wondering if you've just spent a good chunk of money on... thickened water?

WATCH: A cosmetic doctor explains the science behind salmon DNA in skincare. Post continues below.

My skin has been through almost every phase imaginable.

Painfully dry and dull. Oily enough to fry an egg. Random bursts of adult acne. Currently, I'm noticing the first signs of ageing.

The upside is all these phases have given me the chance to really figure out which serums do what they claim.

After years of trial and error, the list of products I purchase with my own money (and recommend to anyone who asks) is surprisingly concise.

So, if you're staring down the endless selection of serums online or in-store, wondering what's actually worth your money, I've got you.

This is my list of trustworthy serums I always come back to, no matter what mood my skin is in.

There's a pick here for every skin type and budget.

Best serums for very dry skin.

ZEROID Intensive Hydrating Ampoule, $68.48.

Image: Amazon.

This underrated Korean gem is developed by dermatologists and delivers serious hydration that rivals the luxury formulas, without the hefty price tag.

If your skin is super dry, I previously reviewed Zeroid's moisturiser and definitely recommend.

Alpha-H Vitamin E Serum With 1% Ceramide Complex, $85. 

Image: Adore Beauty.

This milky first-aid serum helps calm redness caused by dryness and irritation, thanks to ceramides and vitamin E.

Best serums for dehydrated skin.

Anua PDRN Hyaluronic Acid Capsule 100 Serum 30ml, $26.95 (normally $42).

Image: Lila Beauty.

A top-rated K-beauty serum packed with hyaluronic acid capsules and PDRN (derived from salmon sperm) to deeply hydrate, plump and leave your face feeling soft and happy.

Laneige Water Bank Blue Hyaluronic Serum, $68. 

Image: Sephora.

Your skin will drink this up! It delivers deep hydration with zero stickiness and a glow that lasts all day.

Best serums for oily skin.

The Ordinary Supersize Niacinamide 10% + Zinc 1% 60ml, $17. 

Image: Adore Beauty.

This budget-friendly staple helps keep oil, shine and congestion in check, without drying you out.

asap super B complex 30ml, $93.75. 

Image: Adore Beauty.

This Aussie-made serum is jam-packed with B vitamins and a shot of hydration.

It makes sense that it has a 4.7 out of five-star average rating from over 1,000 reviews on Adore Beauty alone.

Skinstitut 10% Niacinamide Power Serum, $69. 

Image: Adore Beauty.

A powerhouse niacinamide serum that helps regulate oil production, refine pores, calm breakouts and even out your skin tone.

Best serums for acne-prone skin.

La Roche-Posay Effaclar Ultra Concentrated Serum 30ml, $64.95.

Image: Adore Beauty.

This drugstore serum seriously unclogs pores, smooths texture and tackles acne, without irritating your skin barrier.

Anua Azelaic Acid 10 Hyaluron Redness Soothing Serum 30ml, $31.80 (normally $42). 

Image: Lila Beauty.

If you're on #SkinTok, you've probably heard about the wonders of azelaic acid for acne and PIE (post-inflammatory erythema; the red, pink or purple marks left on the skin after acne heals).

This top-rated serum soothes, brightens and fights breakouts, which is perfect if your skin is both angry and sensitive.

IT Cosmetics Bye Bye Breakout Salicylic Acid, $65. 

Image: Sephora.

An effective blemish serum that targets stubborn spots with its powerful, albeit gentle, combination of salicylic acid and lactic acid.

Best serums for sensitive skin.

Dermalogica Circular Hydration Serum, $86.40 (normally $108). 

Image: Adore Beauty.

This is the serum you call in an emergency.

Try a few drops of this when your skin is feeling tight, flaky or just a little bit off.

Skin1004 Madagascar Centella Asiatica Ampoule 100ml, $22.50 (normally $30.50). 

Image: Lila Beauty.

This is a cult-favourite calming serum that delivers hydration and healing, formulated with a centella, a common Korean skincare ingredient.

Anua 7 Rice Ceramide Hydrating Barrier Serum 50ml, $24.95 (normally $35).

Image: Lila Beauty.

I owe my life to this serum — it was a huge help after a chemical burn on my face.

One week of consistent use and this will hydrate, soften and strengthen your skin barrier.

Best serums for dark spots.

VT Cosmetics Reedle Shot 300 50ml, $42.95 (normally $65).

Image: Lila Beauty.

You've probably heard about this innovative Korean serum that uses micro-needling tech to target dark spots and texture, without the downtime.

I rate it; read my full Reedle Shot serum review here.

Medicube Glutathione Glow Serum, $36.

Image: Adore Beauty.

A radiance-boosting formula that helps fade the appearance of pigmentation and makes dull skin actually glow.

Eqqualberry Vitamin Illuminating Serum 30ml, $32.50 (normally $45).

Image: Lila Beauty.

Packed with brightening vitamins, this gentle formula is for tired skin that needs a quick pick-me-up.

SkinCeuticals C E Ferulic Vitamin C Serum, $242.

Image: Adore Beauty.

It would be a sin to round up "the best" serums and not include this cult favourite.

The SkinCeuticals vitamin C serum is literally the gold standard for brightening and protecting your skin against premature skin ageing. If you can overlook the price.

Hot tip: Regularly look out for SkinCeuticals deals on Adore Beauty so you can score a decent discount when you decide to add this serum to cart.

Best serums for mature skin.

Medik8 Crystal Retinal 3 30ml, $99. 

Image: Adore Beauty.

This is an effective and beginner-friendly retinoid (vitamin A) serum that smooths the look of lines and promotes collagen production.

K-Secret Seoul 1988 Serum: Retinal Liposome 2% + Black Ginseng 30ml, $22.50 (normally $35). 

Image: Lila Beauty.

This K-beauty serum combines retinoid power with ginseng to firm, brighten and nourish skin, especially the mature type. You can read my full review here.

Eqqualberry Bakuchiol Plumping Serum 30ml, $32.50 (normally $45). 

Image: Lila Beauty.

A gentle, plant-based alternative to retinol that will leave skin plump with the most incredible glow.

It's also perfect for both morning and nighttime use.

VT Cosmetics PDRN Essence 100 30ml, $44.95 (normally $72). 

Image: Lila Beauty.

A luxurious anti-ageing serum for aged, thinning skin formulated with PDRN to target loss of elasticity.

Numbuzin No.9 NAD Bio Lifting-sil Essence 50ml, $34.95 (normally $55).

Image: Lila Beauty.

This Korean skincare product has been dubbed "Botox in a bottle"…

My verdict: It's effective, gentle enough for sensitive skin, and, thankfully, very affordable (especially considering the concoction of top-quality ingredients it's formulated with).

Read my full Numbuzin No.9 NAD Bio Lifting-sil Essence review here.

Have you tried any of these serums? Share your thoughts in the comments section below.

At Mamamia, we independently curate and write about products we rave about in our group chats and think you should know about too. If you purchase a product we have recommended, we may earn a small commission.

Feature image: Supplied.