Does a lidocaine patch actually work for pain?

How a lidocaine patch actually works on pain

Here's what it does versus what you're hoping it does. Lidocaine is a topical anesthetic, and at 4 percent this patch is strong enough to genuinely numb the surface nerves under the skin, not just the skin itself. The adhesive layer holds the medicated pad against your skin for up to twelve hours, and the lidocaine slowly moves through the outer layers of skin to the nerve endings sitting just below it. Those nerves are what carry the ache signal up to your brain in the first place. Once they're desensitized, the signal gets dampened right at the source, before it ever becomes a sharp, distracting pain. The body part of this is simple: lidocaine blocks sodium channels in nerve cells, which is the mechanism that lets a nerve fire a pain signal at all. No firing, no signal, no ache you can feel, at least for as long as the patch stays on and active. That's why it works well for the achy, surface accessible kind of pain, a strained lower back, a sore knee from arthritis, a bruise, and less well for pain that starts deep in a joint capsule or travels along a nerve root, like sciatica, where the patch simply can't reach the source. The patch is large enough to trim to the exact sore spot, which matters more than it sounds, since lidocaine only works where it physically touches skin. It's a single use application, so the twelve hours you get is the twelve hours you get, not a top up supply.