New laws come into force today aimed at protecting consumers from potentially damaging herbal medicines.
Under a European directive, herbal medicines on sale in shops will have to be registered.
Products must meet safety, quality and manufacturing standards, and come with information outlining possible side-effects.
The Medicines and Healthcare Products Regulatory Agency (MHRA) said there had been 211 applications for approval, with 105 granted so far and the rest still under consideration.
Some herbal practitioners fear the move could threaten their businesses.
Commonly used ingredients already registered include echinacea, used against colds, St John's wort, used by some for depression and anxiety, and valerian, claimed as a natural remedy for insomnia.
Research conducted for the MHRA in 2009 showed that 26 per cent of UK adults had taken a herbal medicine in the past two years.
The agency said it is hoping to promote a more cautious approach to using herbal medicines after the study findings found that more than half of people - 58 per cent - believe the products are safe because they are natural.
The agency said there had been a number of health alerts over unlicensed herbal medicines over the years.
In February the MHRA issued a warning about the herbal weight loss product Herbal Flos Lonicerae (Herbal Xenicol) Natural Weight Loss Formula after tests showed it contained more than twice the prescribed dose of a banned substance.