REVEALED: The truth behind Kim Kardashian’s salmon sperm facial and the little known side effects of the $500 beauty treatment also loved by Jennifer Aniston

Kim Kardashian revealed she’s been trying out a new beauty trend that involves injecting salmon sperm into your face.

During an episode of Keeping Up with the Kardashians, the 43-year-old told her mother Kris Jenner on set, “I got a salmon sperm facial, where they injected salmon sperm into my face.”

In addition to Botox-like effects, salmon sperm injections (also called polynucleotides) are said to give clients a “baby face” and rejuvenated skin.

Kris couldn’t help but laugh at Kim, who knows how to handle bizarre facial treatments. But the treatment, which can cost up to £400, can also have some unwanted side effects.

The beauty trend can leave your skin bruised and covered in blood spots, according to proponents of the wrinkle-defying tweak. But estheticians who offer the treatment claim the bruising is only temporary.

One TikTok user with nearly 10,000 followers who had the treatment said she “looked like a complete idiot eating dinner.”

She showed her face after getting the injection, covered in small bumps, dried blood spots and small bruises.

“Salmon seed is basically a baby face and that’s what I’m going through right now,” she said.

“I have little bumps and bruises on my face. But beauty is pain, right?”

A Surrey beauty nurse with just over 1,000 followers also posted a photo of her face just after having the treatment under her eyes.

Although the video showed her eyes visibly swollen, she said the treatment caused “minimal” pain and she “could barely feel it.”

She added that she had a “little swelling” which went down that evening and was completely gone by the third day.

In another TikTok video, posted by someone with more than 4,800 followers, she is seen getting the injections at a clinic.

Afterwards, her face was bumpy and covered in blood. However, at the end of the video, she shared that her blemish-free skin was completely healed.

Proponents say polynucleotides offer a “natural” alternative to other traditional “alteration” procedures such as Botox and fillers.

Some doctors claim it is safer than other cosmetic injections, which have been linked to a range of complications, including clogged blood vessels, bumpy skin and infections.

Usually, purified and sterilized DNA molecules are used for this, which are extracted from salmon or trout sperm. These molecules are called polynucleotides and have an anti-inflammatory effect.

The South Korean beauty industry has been using the treatment for more than a decade, but now it’s gaining popularity among Western celebrities, including Jennifer Aniston, who told The Wall Street Journal that she benefits from its skin-rejuvenating properties.

When polynucleotides, DNA molecules extracted from fish sperm, are injected into human skin, fibroblasts are activated.

Fibroblasts are stretchy molecules found in the skin that help maintain the structural framework of the tissue. As we age, these fibroblasts decrease.

When the polynucleotides are injected under the eyes, into the cheekbones or on the neck, they theoretically “rejuvenate” the skin.

While they are ‘safer’ than fillers or Botox, they are still painful and can cause bruising, experts warn.

Emma Wedgwood, a beauty nurse who works at a Harley Street clinic and provides the treatment, compares the initial side effects of bumpy skin to ‘bee stings’.

But she told MailOnline that this bumpy swelling goes down within a day or two.

“Sometimes you get bruises, depending on where you inject,” she said.

‘Usually it is the more sensitive areas, such as the eyes, that are most susceptible.

‘But it is not comparable to fillers, where you would almost certainly expect bruising with fillers and it is a bonus if that does not happen. With polynucleotides it is exactly the other way around.’

Once the swelling has gone down and the skin begins to heal, it may take months before the full wrinkle-reducing effect is visible.

Mrs Wedgwood said: ‘It can be frustrating for the patient because they have to wait.

“You have to count on about three to six months to see the full effects. So it’s not an overnight job.”

Aesthetic nurse Amanda Azzopardi also offers polynucleotides at her clinics in London, Liverpool and North Wales. She explains that the injections will damage the skin, just like any other injectable.

Because a very thin needle is used and the product is not thick, “the bruising will not be extensive,” she says.

Patients should keep in mind that the area will sting for about a minute and that it may take up to a week for the bruise to heal.

“It’s still an injection treatment,” she told MailOnline.

“So you get mild side effects like redness, bruising, inflammation, which last about a week. There is no risk of vascular occlusion.”

However, there is always a risk of an allergic reaction. Ms. Azzopardi said that you should ask about allergies during your medical consultation and mention if you have a fish allergy.