Lash serums and 5 other beauty products a cosmetic scientist would never use.

There's nothing we love more than asking experts about their own beauty routine. Whether it's asking a doctor about the skin products you don't really need or having Sephora employees spill on the best makeup — it's a pervy game that helps us separate the noisy world of marketing from the stuff that's actually worth your coin.

So when we saw cosmetic chemist Dr Michelle Wong share the beauty products she doesn't use — we definitely took note. 

Watch: Speaking of beauty, I tried that viral 10-pump foundation hack. And the results were... surprising. Post continues below. 

"A lot of people have asked me about these and these are quite personal to me," said Dr Wong. "So I'm not saying everyone has to stop using them."

As always, beauty is a 'you do you' game. So if you if you're using and loving anything below — great! This is just what doesn't work for Dr Wong. 

1. Conditioners without silicones.

There's been lots of hate on silicones in the past, but ask any scientist or cosmetic expert and they'll tell you silicones used in beauty products are actually a very good time — both for hair and skin. 

In fact, it's one of the first things Dr Wong mentioned. She said she'd never use hair products without checking they're on the ingredients list.

"Before I bleached my hair, it was super smooth and straight Asian hair, and [using] any conditioner would be fine. It was actually kind of annoying because I couldn't review hair products well," she shared. 

"But now that I've bleached it all the way to white before putting purple in it — it's a very different story. It needs silicones. Silicones are amazing."

Silicones basically coat your hair (and skin!), blocking out humidity and leaving it feeling smooth, soft and soft and sleek. So, it's a great ingredient for people with dry or frizzy hair!

2. Lash serums.

Specifically, lash serums with an ingredient called 'prostaglandin analogues', which is mainly used to treat glaucoma. As Dr Wong explained, there are many people who regularly use eyelash growth serums without realising the potential dangers.

"This is stuff that works like Latisse," she shared. "There are side effects — for example, they can change your eye colour and reduce the fat around your eyes and make them look sunken. It's pretty crappy of brands to put them in there because they should really be drugs."

There are so many formulas out there, ranging from prescription serums to boost your lash growth cycle to over-the-counter lash 'enhancing' formulas that work to strengthen and condition lashes. So, before buying into the hype, always check the ingredients list and know the safety of every product isn't guaranteed and they could pose risks. 

"It's not all lash serums, but just make sure that you look up the ingredients before you buy one, so you know what you're getting into."

3. Mascara. 

Ask any beauty-obsessed Youbie and she'll tell you mascara is her desert island product. So we also had a heart attack hearing it's on the list of things Dr Wong would never use — but she has a pretty good reason for it.

 "I have trichotillomania which is where I pull my lashes out when I'm stressed. It's apparently a pretty common ADHD thing, and mascara just reminds me that my lashes are there and it makes it worse."

Enough said!

4. Products with MI.

Apparently the preservative MI (the full, long, science-y name is 'methylisothiazolinone') is a very common irritant that's found in beauty products — and it can cause a lot of havoc on the skin. It's a strong allergen and is commonly responsible for skin conditions such as allergic dermatitis. So, it's one to be wary of if you're experiencing skin irritations, flare-ups and redness.

"If you're not allergic to it, it really isn't a problem. I'm not really allergic to a lot of stuff in skincare but this is one — it makes me itch, and it's also in laundry detergent. So if you find you're itchy with some clothes and sheets and stuff — that might be something to look into."

5. Products that smell bad.

You either love fragrances in products or you hate 'em. And Dr Wong is firmly on the no-scent squad.

"If they're too strong or too floral or too — I hate [using] this [term] but, 'chemically'.... I'm in my 30s and I am too old to use products I don't like."

Fair call! For Dr Wong, fragrance-free products are her preference.

"I'll use [products] long enough to do a decent review because my scent preferences aren't the same as everyone else's scent preferences. But once that's done, I am done."

6. Products with bad packaging. 

There's nothing worse than dropping a decent amount of money on a product, only to use it and find it has the world's worst packaging. 

"It's not really something you notice unless it's bad. Like a squeezy tube with super runny product in it. Or a product that's just too thick or lumpy, or if it violently flies out of the pump," Dr Wong said. 

Feels.

Wanna hear more from Dr Michelle Wong? Course you do! Follow her here.

Do you use any of the above beauty treatments? What are your thoughts? Share them with us in the comment section below.

Feature image: Instagram/@labmuffinbautyscience/Canva.