The Food and Drug administration's recent proposal to ban the sale of baldness remedies is a good illustration that rooting out the real meaning of a government action can be tough.

Announced on Jan. 14, the FDA proposal would ban the sale of all nonprescription drug products sold to prevent or reverse baldness. FDA took that action, officials said, because there is no scientific evidence that such lotions and creams work and because these products "represent an area of considerable consumer fraud."

But conversations this week with the agency's public information office show that the proposal doesn't completely cover the problem.

Here are three gaps:

* The proposed ban isn't expected to become final for months, perhaps even years, said FDA media spokesman William Grigg. In the meantime, there is little to prevent the continued sale of nonprescription drugs that claim to prevent baldness, even though the FDA says that none of them has been shown to work. Consumers who have purchased such products and now want to get their money back can ask for refunds, he said, but there is no assurance they will get any.

* The proposed ban doesn't cover cosmetic products that claim to prevent or reverse baldness. "Their pitch is that their product cleanses the follicles and releases hair growth that had been blocked," said Bruce M. Brown, another FDA representative. "There is no evidence that these products, which are usually sold by clinics, can grow new hair or slow the loss of existing hair. But since the FDA has not established that their product is a drug rather than a cosmetic, the ban wouldn't extend to them."

* The proposed ban does not address the problem of the prescription drug, minoxidil, which was developed to treat hypertension but which apparently can trigger the growth of hair in certain individuals. The FDA has approved the use of minoxidil in capsule form for hypertension, Brown said, but the agency hasn't approved the use of the drug for hair growth.

Does minoxidil work?

"It does grow fuzz for a small number of people," Brown said, "but the fuzz stops growing when you stop using the drug."

Even though results are uncertain and even though the drug doesn't have FDA approval, "free-lance" operators have been advertising minoxidil treatments as a hair growth product, Brown said.

He said that the FDA doesn't have any statistics on the estimated annual sales of baldness-prevention products. But a 1984 agency-sponsored review of 435 newspaper and magazine ads found that hair restoration schemes are next in popularity to diet hoaxes, he said.

Of the 89 hair-restoration advertisements reviewed, 42 were for products and 47 were for clinical treatments, Brown said.

He said that baldness-prevention products typically are advertised in magazines and newspapers and sold through the mail for $10 to $20. There also have been reports of the products being sold in drugstores.

The clinical treatments for hair loss, Brown said, can cost $200 or more. "They usually locate in affluent urban areas, where they get foot traffic and people who can pay their prices," he said. "They generally charge by the month, and although they have a money-back guarantee, you aren't eligible until after you've paid two or three months."

The point for consumers to remember, Brown said, is that neither the treatments nor the products have been found to work. "Nothing works, except hair transplants," he said, in which a person's own scalp hair is grafted onto another part of the scalp.

But hope has a way of "short-circuiting reality," Brown said. And as long as consumers are willing to spend money on baldness cures, he said, there will be people who will circumvent FDA rules to sell them.