What is the most effective way to stop leaks from the stem of a faucet?

To effectively stop leaks from the stem of a faucet, replacing the packing is the best approach. The packing, which is a type of material used to create a seal around the faucet stem, can wear out over time due to repeated use. When the packing becomes damaged or compressed, it no longer provides a watertight seal, leading to leaks.

By replacing the packing, you restore the seal around the stem, which prevents water from escaping and effectively resolves the leak. This solution not only addresses the immediate problem but also prolongs the life of the faucet by ensuring that it functions properly.

Other methods, while they may seem intuitive, do not directly resolve the issue of leaking from the stem. For instance, replacing the handle or changing the valve addresses different parts of the faucet's mechanism rather than the source of the leak itself. Applying sealant might offer a temporary fix but is not a permanent or reliable solution for a leaking stem, as it does not address the underlying wear of the packing that leads to the leak.