Filters should not be applied to social media adverts if they exaggerate the effect of the product, the Advertising Standards Authority has ruled.

The ASA was responding to the #filterdrop campaign that called for it to be compulsory for influencers to state when they use a beauty filter to promote skincare or cosmetics.

Sasha Pallari, who started the campaign, said she was "over the moon".

The ASA said filtered beauty content could be "misleading".

Miss Pallari, 29, from Weston-super-Mare, said she started #filterdrop in July 2020 in the hope of seeing "more real skin" on Instagram.

The use of filters on social media is a widely debated issue, attracting the attention of not only celebrities and social media influencers but also MPs.

The ASA examined two examples of where filters had been added to videos shared by influencers advertising tanning products, adding that the outcome of these rulings would apply to all UK brands, influencers and celebrities.

They were: two Instagram stories for Skinny Tan Ltd and one for Tanologist Tan which was banned for applying a filter that "misleadingly exaggerated the effect the product was capable of achieving".

It ruled the ads in both cases were likely to have misled consumers.

It said the ruling means that brands, influencers and celebrities should not apply filters to photos that promote beauty products if the filters are likely to exaggerate the effect the products are capable of achieving.

The ASA said that filtered beauty content could still be misleading, even if the name of the filter was referenced in the Instagram story.

Ads that break these rules would be taken down and prohibited from appearing again, which was likely to damage the advertiser and influencer's reputation, the ASA said.

A spokesman said: "An ongoing focus of our work in this area continues to be on raising awareness of the rules and supporting influencers with the guidance and tools they need to help get their ads right.

"We're also working closely with the social media platforms who can and will enforce our rulings where an advertiser is unwilling or able to work with us."

Miss Pallari said: "I feel like the detrimental effect this is having on social media users has finally been taken seriously and this is a huge step in the right direction for how filters are used and the way cosmetics are advertised online."

She said it was an issue she had been passionate about for a long time and she received messages "every day" from women struggling to match the beauty standards in real life that they see online.

"I can now help make a difference to how these women view themselves in the mirror and that's amazing," she said.

Molly Nutt, 20, has been following Miss Pallari's campaign and welcomed the ruling, adding that much of her life has "revolved around filters".

"Filters with names like 'Pretty Girl', with blue eyes, bigger lips and a smaller nose, that just implies what you should look like, and not everybody is going to look like that," she said.

"Not everyone is an expert at make-up... and then with the filters as well it enhances it even more... I can't match up to how they look on Instagram.

"Most days I couldn't even leave the house without putting on make-up, but now I don't care as much... Sasha has made me feel more at ease with who I am and that I'm not an alien because of the way I look."

With more than 900,000 followers on Instagram, model and influencer Rahi Chadda, said he "completely agrees" with the ruling but is concerned about how it will be policed.

"Having this ruling is a step in the right direction," he said.

"The logistics though will definitely be a point of concern for the majority of influencers, because what is the definition of a filter?

"When we are talking about filters, are we talking about lighting, special effects, make-up before promoting a product... in that way most pictures on social media will be naturally filtered... you have already glorified the product in such a way before it is reaching the audience.

"They are going to have to be a lot clearer about what they mean by a filter and where we draw the line."

When Miss Pallari set out on her campaign, she said she wanted to see three outcomes: to encourage as many women as possible to not depend on filters, for the ASA to demand that social media influencers and celebrities must state if they have used a filter when promoting cosmetics and to get face-changing and morphing filters removed from Instagram.

She said with two of her aims achieved, she would fight to get face-altering filters removed from Instagram altogether.

"There's no point coming this far, to only come this far," she said.

"How can Instagram agree to remove filters that promote plastic surgery, but not filters that alter your shape - how else are we going to alter our face without plastic surgery?"

The most recent celebrity to speak out about face-altering filters is former Little Mix singer Jesy Nelson.

She took to her Instagram feed on Tuesday to encourage her 7.6m followers to embrace their natural looks.

The 29-year-old said while she "loves a little Instagram filter that makes you look a bit more tanned or your skin a bit fresher", she does not understand why most filters alter her appearance, giving her a "tiny nose and huge lips".

She went on: "I don't understand why Instagram feels the need to squash your nose and make it really skinny. What's wrong with a standard nose?

"I'm so confused why whoever makes these filters think that is what beauty is?"

Responding to the ASA ruling, Skinny Tan said it had since reviewed its guidelines on the user-generated content it chose to share on social media.

"We do not encourage the use of beauty filters that exaggerate or provide a misleading impression of the results our products can achieve," a spokeswoman said.

"Whilst we were disappointed with the ASA ruling, as the intention behind the particular Instagram stories in question was not to mislead but rather to share her positive comments and experience with using our products, we do fully understand our responsibility as a brand to protect consumer interests.

A spokesperson for Tanologist said it was disappointed but respected the ASA's ruling, although it had not used the content on its brand account.

"The influencer content in question demonstrated before and after self-tan product results.

"The 'after' content - which depicted the results of the self-tan product - did not have a filter applied."

When approached for comment about the #filterdrop campaign and the ASA ruling, Instagram declined to comment, but the BBC understands that brands, celebrities and influencers are asked to comply with CMA and ASA guidance on sponsored social media posts.