When you have a sore knee, stiff shoulder, or burning nerve pain from shingles, swallowing pills isn't always the best answer. Many people don’t realize that powerful pain relief can come from something you rub or stick right on your skin. Topical analgesics - like lidocaine patches, capsaicin gels, and NSAID creams - work directly where the pain is, without flooding your whole body with drugs. They’re not magic, but for a lot of folks, they’re the smartest first step.
How These Gels and Patches Actually Work
Not all topical pain relievers are the same. Each one attacks pain in a completely different way, and knowing how they work helps you pick the right one.
Lidocaine, found in patches like Lidoderm®, is a local anesthetic. It blocks the electrical signals that travel along your nerves. Think of it like cutting a wire - the pain message never reaches your brain. A single 5% lidocaine patch releases just enough into your skin to numb the area, but barely any enters your bloodstream. Studies show peak blood levels are only about 10% of what’s needed to affect your heart. That’s why it’s safe for people who can’t take heart or liver medications.
Capsaicin, the stuff that makes hot peppers burn, works differently. It starts by overloading your pain nerves with a burning sensation - yes, it hurts at first. But then, it burns them out. Capsaicin binds to TRPV1 receptors, which are basically the alarm buttons on your pain-sensing nerves. After repeated use, those nerves get tired and stop sending signals. The 8% patch (Qutenza®) is strong enough to need a doctor’s application, but it can knock down nerve pain from shingles for weeks. Plasma levels? So low they’re almost undetectable.
NSAID gels, like Voltaren (diclofenac 1%), work like oral ibuprofen - but only where you put them. They block COX enzymes that make inflammation chemicals (prostaglandins) right at the joint or muscle. Microdialysis studies show tissue levels can be 10 to 100 times higher than in your blood. That means serious pain relief without the stomach upset or kidney strain you get from pills.
What Each One Is Best For
Not every patch or gel works for every kind of pain. Here’s what the data says:
- Lidocaine patches are best for localized nerve pain, like postherpetic neuralgia (the lingering burn after shingles). They’re also handy for small, well-defined areas like a scar or a single sore joint. The Cochrane Review found an NNT (number needed to treat) of 6.7 - meaning about 7 people need to use it before one gets clear relief. Not amazing, but safer than pills for older adults.
- Capsaicin (8% patch) shines for neuropathic pain. For postherpetic neuralgia, it has an NNT of 4.4 - better than lidocaine and close to oral meds like pregabalin. But here’s the catch: the first application feels like a firework on your skin. Most people quit before the second use. That’s why it’s only done in clinics - a nurse applies it, waits 30 minutes while you ride out the burn, then wipes it off. The relief lasts 3 months or more.
- NSAID gels are the go-to for osteoarthritis, especially in knees and hands. A 2022 study found 60% of patients saw major pain reduction in 4 weeks. For hip pain? Only 20%. Why? Because the gel can’t reach deep joints. But for surface joints, it’s as good as pills - and with 97% fewer stomach problems. The European Medicines Agency says it’s safe for most, but warns people with heart disease to use caution.
Real-World Results: What Patients Actually Say
Numbers tell one story. Real people tell another.
A 2019 survey of 250 chronic pain patients found 68% got moderate to significant relief from NSAID gels. Seventy-two percent said they preferred the gel over pills because they didn’t get stomach pain or dizziness. But 45% said the relief was inconsistent. Why? They didn’t use enough. Most people squeeze out a pea-sized amount. The label says 2-4 inches of gel - about the length of your index finger. You need that much to cover the whole area.
Reddit users shared blunt truths. One person wrote: "8% capsaicin patch dropped my shingles pain from 8/10 to 3/10 - but applying it felt like a burn injury. Worth it, but brutal." Another said: "Voltaren takes 45 minutes to kick in, but then I’m good for 6 hours. No nausea. No sleepiness. I use it every day."
Side effects are real. About 10-30% of users get redness, itching, or a rash where they apply it. Lidocaine patches cause mild skin irritation in 5-15% of users. Capsaicin? Up to half the people quit because of the initial burn. NSAID gels are the least irritating - but if you apply them to broken skin, you risk absorbing too much.
How to Use Them Right (And Avoid Mistakes)
These aren’t like lotion. Mess up the application, and you get no relief - or worse.
- Lidocaine patches: Use no more than three per day. Leave them on for 12 hours, then take them off for 12. Don’t cut them. Don’t reuse them. Don’t apply heat (like a heating pad) over them - that can spike absorption and cause toxicity.
- Capsaicin: Always wash your hands after applying. Never touch your eyes, nose, or mouth. The 8% patch is only for professionals. OTC capsaicin (0.025-0.1%) is weaker and needs daily use for weeks before you feel anything. Be patient.
- NSAID gels: Apply four times a day, at least 4 hours apart. Rub it in gently for 1-2 minutes - don’t just smear it. Wait 30 minutes before covering the area with clothing. Don’t use it on open wounds. And don’t combine it with oral NSAIDs - you’re doubling your risk of side effects.
Most people get it wrong on day one. A study found 60% used too little gel. Another 25% applied it to cuts or rashes. The fix? Watch the video that comes with prescription patches. For OTC gels, read the label twice. If it doesn’t say how much to use, ask your pharmacist.
Who Should Use Them - And Who Should Skip Them
These are great for:
- Elderly patients with osteoarthritis (42% of Medicare users take them)
- People with stomach ulcers, kidney disease, or liver problems
- Those on multiple medications - they rarely interact
- Anyone avoiding opioids or NSAID pills
Avoid them if you:
- Have an allergy to any ingredient (check labels - some gels contain alcohol or preservatives)
- Have open wounds, infections, or severe eczema at the application site
- Are pregnant - NSAID gels aren’t recommended in the third trimester
- Have severe heart disease - even topical NSAIDs carry a small risk
The Future: What’s Coming Next
The market for these products is exploding. It hit $5.2 billion in 2022 and is expected to hit $8.7 billion by 2028. Why? Because people are ditching opioids and pills.
New tech is on the horizon. A 2023 trial tested a nanoemulsion version of diclofenac - it delivered 2.3 times more drug into the tissue without raising blood levels. That means better pain relief with even less risk.
Researchers are also testing resiniferatoxin (RTX), a supercharged version of capsaicin. It’s 1,000 times stronger. Early results show it could reset nerve pain for over a year - but it still can’t get deep enough into skin. Scientists are working on gels that carry it further.
The goal? Targeted pain relief without touching your liver, kidneys, or stomach. Topical analgesics aren’t the cure-all - but for localized pain, they’re becoming the new first choice.
Can I use lidocaine patches and NSAID gel together?
Yes, you can - but not on the same spot. Use lidocaine for nerve pain and NSAID gel for joint inflammation. Apply them to different areas of your body. Never mix them on the same patch of skin. There’s no proven interaction, but layering them might irritate your skin.
How long does it take for capsaicin to work?
It depends on the strength. OTC capsaicin (0.025-0.1%) takes 2-4 weeks of daily use before you feel relief. The 8% prescription patch works faster - pain relief starts within days, and effects last up to 3 months. But the first application causes intense burning for 30-60 minutes. That’s normal and means it’s working.
Are topical NSAIDs safer than oral ones?
Yes, significantly. Oral NSAIDs cause about 1.5% of users to develop stomach ulcers. Topical versions? Only 0.03%. They don’t flood your system, so your stomach, kidneys, and liver are mostly spared. But if you have heart disease, even topical NSAIDs carry a small risk - talk to your doctor before starting.
Can I use these if I’m on blood thinners?
Lidocaine patches and capsaicin are generally safe. NSAID gels are low-risk, but they still have a tiny chance of affecting blood clotting. If you’re on warfarin, clopidogrel, or similar drugs, ask your doctor. Most will say it’s okay, but they’ll want to monitor you.
Do these work for back pain?
Only if the pain is near the surface - like muscle strain in the lower back. If it’s deep, from a disc or joint, topical gels won’t reach it. They’re not meant for whole-back pain. For that, you’ll need physical therapy, oral meds, or injections. But if your pain is localized to one spot - say, a tender spot above your hip - a lidocaine patch or NSAID gel can help.
Can I use these with a heating pad?
No. Heat increases how much of the drug your skin absorbs. With lidocaine, that could lead to toxicity. With NSAIDs, it raises your risk of side effects. With capsaicin, heat makes the burning worse. Always let the product work at room temperature.
