Image: Luci Leptos.

It started off as a typical night out. Luci Leptos got ready, applied some red lipstick then headed out the door to meet her boyfriend for dinner and a concert.

As she made her way to the concert after dinner, the 20 year-old soon suspected something was not right.

“I felt really funny and light headed after eating and then it just felt like I’d gone for a run but I hadn’t even walked far at all,” she says.

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“My heart was going so fast in bursts, then would slow down, then speed up again – it just kept doing that.”

“I thought it would sort itself out so it took quite a bit of convincing to get me to go to hospital but after speaking to them [a doctor] they were concerned with what they heard,” she says.

“By the time I got there they palpitations had gone down quite a bit, so it was all over very suddenly but I imagine they’d have put me on fluids for a while if my heart had kept going nuts.”

After doing a blood test, doctors noticed the results showed strange levels of phosphorus, which were the only values not completely normal.

Given both Leptos and her boyfriend had eaten and drank the same stuff the entire night, the hospital suggested that the lipstick could have been the cause of her heart palpitations.

"They said it was very possible that it was the lipstick I was wearing. There wasn't any other reason for me to get like that, and I've never had anything like it before or since," she says.

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"It was just a really crappy red lipstick from one of those cheapo bins you see at cosmetic stands where everything is $1, although I can't remember the exact brand - that lipstick is long gone!" she says.

"The day after I still felt a little bit lightheaded for the morning but then it all cleared up by the afternoon. That was the first and only time I've ever used a cheap lipstick and that happened, so I'm definitely putting the hospital visit down to that."

Unfortunately, this story is not an isolated case. As online shopping has grown, so too has the sale of of "fake" beauty products. (Post continues after gallery.)

How to spot fake makeup

Makeup brushes and other accessories on white table

Packaging Packaging on counterfeit products can be one way that you can try and determine their authenticity but beware, a lot of time and money goes in to replicating big name brands so its not always easy.

Be familiar with the real packing before you start looking around. Anything that doesnt match EXACTLY should be discounted immediately.

Next look at details like font, colours, spelling and layout. Reputable makeup brands have highs standards when it comes to their packaging so if the wording seems off centre, or the font is a little smudged, move along. Look at the spacing between words, it should all be uniform. And if you see a seller who has a lot of items without original packaging, beware!

Makeup Brushes.

QualityObviously this can be tricky when youre looking online but colours and pigments can be a huge giveaway when it comes to assessing a products authenticity.

Pigments in well made products are strong and vivid. If the one you have is chalky and faint, its not the real deal.

Also, if the colour swatches of the products online look different to those on the brands website alarm bells should be ringing.

buying foundation online 4

ResearchBefore agreeing to purchase an item from an eBay seller, take the time to view their feedback. If someone else has raised concerns about receiving a counterfeit product, chances are youll be getting one too.

buying foundation online

Big DiscountsHave you ever noticed that big name makeup brands like MAC, NARS, Clinique and Bobbi Brown never go on sale (they may have promotions but the items themselves are never discounted). Thats because they dont have to. The market will pay the asking price so theres no need to sweeten the deal with discounts.

If you see a Benefit blush in store for $35, and then spot the same one online for under ten, youve gotta start asking some questions.

Remember a seller wouldnt sell unless theyre making a profit so if theyre able to list an item for well below store RRP, there must be something suss going on.

This is largely because it becomes much more difficult to check the authenticity of products before you buy online, particularly with the rife use of genuine stock images to promote fake products.

While it's true cosmetics can be expensive, you're not just paying for the name, but also the research, testing and safety measures that ensure a quality product is made for the consumer.

So although they may seem to be a bargain, not only are counterfeit products ripping off your favourite brands, they're also posing a serious risk to your health.

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According to a new awareness campaign launched by City of London police on counterfeit goods, fake beauty products are usually made in unsanitised factories and have been found to contain traces of rat droppings, human urine and even arsenic.

Lab tests have also found that fake cosmetics such as eyeliner, mascara, lip gloss and foundation can contain toxic levels of chemicals and other harmful substances such as mercury and lead.

These can cause allergic reactions including skin irritations, swelling, burns, rashes and even more long-term health problems.

According to City of London Police, Detective Superintendent Maria Woodall, many consumers are unaware about just how dangerous counterfeit beauty products can be.

"Beauty products are meant to enhance your features however the fakes can in fact do quite the opposite. Our general rule is; if it seems to good to be true then it probably is," she says.

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That's not the only concern though.

"Not only could these products have serious implications to your health and wellbeing, but by simply going online and buying from a rogue site or dealer, your personal and financial information is also at risk," she warns.

Fortunately, this shouldn't scare you off online shopping for good - there are plenty of amazing genuine sellers and products out there, but it is important to take caution.

5 online safety tips

1. Trust your instincts

If an offer looks too good to be true, then it probably is. Legitimate designer items are rarely discounted, so do not rush and be fooled into believing you are getting a good deal.

2. Check for spelling errors

Check the spelling and grammar on the website and the URL - often the people behind these sites do not pay a lot of attention or care to this detail. Fraudsters may also try to deceive you by slightly changing the spelling of a well-known brand or shop in the website address.

3. Check out sellers online

Only use sites you know or ones that have been recommended to you. If you have not bought from the seller before, do your research and check online reviews.

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4. Safety first

Ensure the website begins 'https' at the payment stage - this indicates a secure payment. If you're not sure whether the items are genuine, do not enter your payment details - it's not worth the risk.

5. Check returns

Ask the trader if there is a returns policy or guarantee. Most rogue traders will not offer this.

There's no need to buy the fakes to save money - check out our favourite budget versions of beloved (more expensive!) products.

The ultimate guide to beauty dupes

High: NARS Blush in Orgasm

Dupe: NYX Cosmetics Blush in Peach

High: YSL Touche Eclat Radiant Touch

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