XLSMedicalUK
The ad, which sparked 200 complaints, was shown on TV, YouTube and on on-demand services. The pills are marketed as a "medical device for general weight management."
The video presents two friends exchanging messages about their upcoming holiday. One woman explains that she lost weight by using the XLS pills, which she says "could help users lose up to three times more weight versus dieting alone."
But the second, who looks miserable but appears in perfect health, says: "Urgh. I'll never fit into my holiday wardrobe."
The first woman then encourages the second to take the XLS slimming pills. Presumably she does because, in the next scene, the pair look ridiculously happy while taking selfies on a beach.
Complainants argued the commercial was irresponsible because it "promoted an unhealthy body image, particularly amongst young girls."
The ASA ruled that the combination of the actress' "already healthy slim appearance" with her "poor body image and confidence" created the impression that weight loss was desirable.
The watchdog ruled the ads must not appear again in their current form and told Omega Pharma Ltd, which commissioned the ad, "to take care to ensure their products were advertised in a socially responsible way."
Omega Pharma Ltd responded that both women in the ad had a Body Mass Index (BMI) of greater than 19kg/m2 - as required by guidelines. Additionally, it pointed out that there was an onscreen message which stressed that the pills "can help slimming as part of a calorie controlled diet & healthy lifestyle."
Complainants also argued the advert was addressed or likely to appeal to children, because it used actresses who appeared under 18-years-old.
This complaint was overruled by the ASA. The actresses were 24 and 29-years-old respectively and the ad came with a scheduling restriction that meant it could not be shown during shows aimed at children.
You can see the full banned advert below: