'As a dermatologist, I've been using these beauty secrets for decades. I refuse to gatekeep them.'

If there's one thing I love doing it's following dermatologists, cosmetic doctors and skin experts on social media and finding out all their juicy insider tricks and tips when it comes to nabbing good skin/hair/face, etc. — including the products and treatments that are actually worth spending on (and the ones that aren't).

Because more often than not you'll find a lot of the 'boring', 'unsexy' products you can pick up at the pharmacy are actually better than some of the expensive, hyped-up stuff out there — and they truly deliver when it comes to results.

So, when I came across this recent post on the products an over-40s skin expert rates, I immediately wanted to tell every beauty girl and her mum.

Watch: Dr Pimple Popper looks back at her favourite squeezes. Post continues below.

In an Instagram post titled, 'Ageing secrets I refuse to gatekeep as a 40-year-old dermatologist', dermatologist Dr Shereene Idriss from the US (@shereeneidriss on Instagram), listed all of the products she swears by for your best skin (and hair). And yes, it sounds just as nosy as you'd think.

So, in the interest of spreading the word on what's actually good and worth your time and money, I've pulled together all her stellar tips into a tidy little list for you below.

Shall we get started?

1. Body acne? Use an antibacterial cleanser.

If you're someone who struggles with breakouts or persistent acne on your butt, back or body, you'll know just how annoying and fickle it can be to treat. Dr Idriss's tip? Opt for something a little more hard-hitting than your usual body cleanser.

"Use Hibiclens on your butt and back to kill bacteria and prevent acne, " she shared. "Caution: Keep out of ears, eyes and mouth (i.e. your head)."While Hibiclens isn't stocked in Australian stores, you can pick it up online on various websites or opt for something like Microshirld 2 Chlorhexidine Skin Cleanser, $19, from the chemist. Similarly to Hibiclens, this is an over-the-counter antiseptic product that uses the same active ingredient (chlorhexidine) to help clear the skin and fight infections by killing bacteria, fungi and yeast.

As Dr Idriss cautioned, just be sure to steer clear of your face when using any antibacterial cleanser.

2. Use retinol eye cream around your eyes and mouth.

Dr Idriss also warned against using prescription vitamin A (retinol) around delicate areas like your eyes and mouth — because things have an awful habit of getting mighty irritated and sensitised around here. And approximately no one has time for half of their face flaking off unnecessarily.

Instead, she recommended using a retinol eye cream like No7 Pure Retinol Eye Cream, $44.99. While still powerful, it's a gentler option that's specifically made with ingredients like shea butter to help the skin feel soothed and hydrated.

3. Anti-fungal shampoo for thicker, fuller hair.

Thin and fine-haired girlies, this one's for you. While there are approximately a million different hair treatments on the market for thicker hair and to reduce hair loss, according to Dr Idriss, a simple anti-fungal shampoo such as Nizoral Anti-Dandruff Shampoo will not only prevent an itchy, flaky scalp but will also help encourage fuller, healthier hair.

*Buys in bulk*.

4. Lip basting for smoother lips.

If you ever read my article on 'face basting' (aka using nappy rash cream for smoother, plumper skin), you'll know the hack originated from Dr Idriss. And apparently, it's also her secret to smoother, plumper lips.

For those with flaky, thin lips, she instructed: "Exfoliate with [a] light percentage of AHA/PHA," before sealing with a "rich emollient".

Whether you want to opt for something like Vaseline or something a little heavier like good old Sudocrem, the acid will work to slough away dead skin cells, while the emollient will act as a protective barrier to keep the lips moisturised and happy.

5. Don't forget your hands.

Dr Idriss also said, "Everything you do for your face, do for your hands," and honestly — WHOOPS. Anyone else been rejecting their hands since birth?

And honestly, since your hands are one of the first places on the body to show signs of ageing — it kind of makes a lot of sense. Due to their thinness and frequent sun exposure, Dr Idriss said we should treat the skin on our hands like the skin on our face and chest — using serums, creams and protecting them with SPF to keep them hydrated, protected and free of dark spots and blotchiness.

We know, we know. Sometimes you've barely got time to wash your face never mind do a full skincare routine for your hands — we get it! If anything, just make sure to slather SPF on them every morning to ensure they're protected from harsh UV rays. Trust us, you'll thank yourself later.

What do you think of the above tips? Would you try them? Share your thoughts with us in the comment section below.

Feature image: Instagram/@shereeneidriss.