The Government has bowed to pressure from MPs, who are worried that doctors and patients are susceptible to ad campaigns by the pharmaceutical industry.
Although ministers will preserve the existing self-regulatory system, ads for new products will have to be cleared for the first time.
The Department of Health is threatening to cut subsidies that help drug companies with research and promotion if they breach the industry's code of marketing practice or run misleading ads.
Replying to criticism from the Commons health select committee, the department insisted the current system was effective. However, it acknowledged there were "concerns" about the actions of drug companies, saying that "proper controls" on marketing were needed.
The department has asked the Prescription Medicines Code of Practice Authority to consider its proposals to strengthen the code to reflect these concerns.
The changes could include limiting the spend or the amount of marketing material for newly licensed products.