Scientists have found a new way to grow hair, one that they say may lead to better treatments for baldness.

So far, the technique has been tested only in mice, but it has managed to grow hairs on human skin grafted onto the animals. If the research pans out, the scientists say, it could produce a treatment for hair loss that would be more effective and useful to more people than current remedies like drugs or hair transplants.

Present methods are not much help to women, but a treatment based on the new technique could be, the researchers reported Monday in Proceedings of the National Academy of Sciences.

Currently, transplants move hair follicles from the back of the head to the front, relocating hair but not increasing the amount. The procedure can take eight hours, and leave a large scar on the back of the head. The new technique would remove a smaller patch of cells involved in hair formation from the scalp, culture them in the laboratory to increase their numbers, and then inject them back into the person’s head to fill in bald or thinning spots. Instead of just shifting hair from one spot to another, the new approach would actually add hair.