Opponents of animal testing for cosmetics said there was "tremendous support" during a protest at the West Sussex headquarters of The Body Shop.
The first Body Shop opened in Brighton 30 years ago
Naturewatch has objected to the £625m sale of the Littlehampton-based business to L'Oreal earlier this year.
It accused the French cosmetics giant of still carrying out animal testing.
L'Oreal said it had not done so since 1989, although it could not guarantee that all ingredients bought from other firms had not been tested on animals.
A spokeswoman said some ingredients still had to be tested under European health and safety rules.
A L'Oreal statement said: "We have not carried out or commissioned tests of products or ingredients on animals since 1989."
Naturewatch said it would continue its campaign until L'Oreal stopped using ingredients which had been tested on animals.
Director John Ruane said Monday morning's protest in Littlehampton had "helped get the message across".
"It's been very good with tremendous support from everybody passing, the horns are hooting all over the place and we think it's been successful," said Mr Ruane.
The protest included a "boycott bunny", while one supporter wore a dress made out of Body Shop loyalty cards which Naturewatch said were sent to them by disgruntled customers.
However, L'Oreal insisted that The Body Shop's Against Animal Testing Policy would "continue to be applied rigorously across the product range".
The policy guarantees that no ingredients contained in Body Shop products are tested on animals.