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Can I take 50 and Lidocaine grunenthal together?

Drug interaction guide

There is no known interaction between 5-HTP (often referred to as '50' in supplement contexts) and Lidocaine Grunenthal (a medicated plaster or local anaesthetic).

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Why this happens

5-HTP is a precursor to serotonin and primarily affects the central nervous system. Lidocaine Grunenthal works locally to numb pain by blocking sodium channels in the nerves. These two substances work through different pathways in the body and do not interfere with each other's metabolism or effects.

You can use these two products together. However, if you are using Lidocaine Grunenthal (the plaster) for post-herpetic neuralgia (nerve pain after shingles), ensure you follow the specific application instructions provided by your doctor. If you experience any unusual side effects, such as extreme drowsiness or skin irritation, contact your healthcare provider.

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Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Disclaimer

This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.

Article history

The information on this page is written and peer reviewed by qualified clinicians.

  • 14 Mar 2026 | Originally published
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