The UK's advertising watchdog has criticised L'Oreal for making "misleading" claims about its wrinkle and cellulite creams.
The 'orange peel effect' is how cellulite is often described
The Advertising Standards Authority said ads for Wrinkle De-crease and Perfect Slim should be banned unless the company can back up its statements.
The ASA said both products only caused cosmetic differences.
But L'Oreal said customers had reported high levels of satisfaction with the products.
The wrinkle cream commercial featured model Claudia Schiffer pulling different facial expressions, giving the impression that the product worked on human face lines, the ASA said.
L'Oreal's advert claimed that 76% of 50 women who self-evaluated the effects of the cream after three weeks reported visible reduction of their expression lines.
It also said the product was "the first anti-creasing cream with Boswelox to counteract skin micro contractions" and could "rapidly reduce wrinkles".
But after an investigation, the ASA ruled that L'Oreal did not have enough evidence to prove that the cream's effect was anything more than cosmetic.
It ruled: "The ASA's expert considered that there was insufficient evidence to allow such a claim about the effect of the product on the human face.
"We therefore considered the advertisement misleading on that point."
The watchdog also upheld complaints about a TV advert which claimed L'Oreal's Perfect Slim cellulite cream had been "judged best anti-cellulite product in an independent study (based on an independent French consumer study)".
The advert had also claimed the cream "visibly reduces the appearance of cellulite (48 women tested; 71% agree)."
An ASA expert found that L'Oreal's consumer study was limited and was not scientifically evaluated.
The watchdog concluded viewers would think the product could eliminate or reduce cellulite but this was not backed up by evidence.
In its judgement, the ASA ruled: "Because the evidence produced was below the standard that would be expected to back up claims relating to physiological action, we did not believe it was sufficient to support the claim that the product could help banish cellulite."
Trials carried out by L'Oreal showed the average improvement was not noticeable to the user, and that half of those using the product had not registered the improvement claimed, the ASA said.
It ruled that the Perfect Slim commercial must not be shown again without "sufficient evidence" to back up its claims.
But L'Oreal said both commercials had been approved by the Broadcast Advertising Clearance Centre on the basis of the "technical substantiation of the product benefits".
It added in a statement: "Both L'Oreal Paris Wrinkle-De-Crease and Perfect Slim have been very popular with customers, demonstrated not just by their overall sales, but also the repeat purchases.
"In addition, research that was presented to the ASA shows a high rate of satisfaction for both products: 92% for Wrinkle De-Crease and 84% for Perfect Slim.
"Although we disagree with the elements of the complaint that were upheld, L'Oreal will comply with the ruling of the Advertising Standards Authority and adapt future advertisements accordingly."