# Scrambler therapy (Calmare) for chemotherapy nerve pain

Source: https://onco.cc/technologies/scrambler-therapy/  
OnCo record `scrambler-therapy` (Technology). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A surface electrical device that is said to replace pain signals with signals the brain reads as normal. People treated with it often feel better, but in the only trial that compared it with a dummy device there was no difference between the two, so what is being felt may be the attention and the expectation rather than the machine.

## Summary

Scrambler therapy, marketed as Calmare, applies low-intensity electrical stimulation through surface electrodes placed around the painful area, usually in ten daily sessions. The claim is that it substitutes synthetic non-pain information for the pain signal travelling in the same C-fibre pathway.

The open-label evidence is encouraging and the controlled evidence is not. In a randomised phase 2 trial of 50 patients comparing scrambler therapy with transcutaneous electrical nerve stimulation, "twice as many Scrambler-treated patients who had at least a 50% documented improvement during the 2 treatment weeks, from their baseline pain, tingling, and numbness scores, when compared with the TENS-treated patients (from 36 to 56% compared with 16-28% for each symptom)". But in the pilot sham-controlled trial, where patients could not tell which device they had, there were "no significant differences between the sham and the 'real' ST group at day 10, 28, 60, or 90, for average pain", and the authors wrote: "We observed no difference between sham and real ST CIPN treatment." Notably, "All 'real' patients wanted to continue treatment if available."

A 2026 systematic review of the randomised trials found only two eligible studies, 35 and 50 participants, of low to moderate quality, and concluded that "Scrambler therapy does not yet meet statistical criteria for a successful treatment CIPN".

This is listed here, graded insufficient, because it is sold to people with chemotherapy nerve pain who will otherwise find only the marketing. It is not dangerous, and a larger sham-controlled trial would settle it.

What comes back, and when: unknown. No controlled trial has shown a change in nerve function, and the only blinded comparison found the dummy device did as well.

## Fields

- Kind: Technology
- Status: emerging
- Last checked: 2026-10-02
- Tags: rejuvenation; survivorship; evidence:insufficient
- Principle: Electrodes placed on intact skin proximal and distal to the painful area deliver patterned low-amplitude current intended to be interpreted centrally as non-painful, on the theory that plastic reorganisation of the pain pathway outlasts the stimulation. The sham comparison is the test of whether that mechanism, rather than expectation, is doing the work.
- Strengths: Non-invasive, no drug interactions, no reported serious harms; Patients in the trials wanted to continue it; A properly powered sham-controlled trial would be straightforward to run
- Limitations: The only sham-controlled trial found no difference from the dummy device; Both randomised trials are small and at low to moderate risk of bias; Ten clinic visits, and usually paid for privately

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Transcutaneous_electrical_nerve_stimulation
- A pilot randomized sham-controlled trial of MC5-A scrambler therapy in chronic chemotherapy-induced peripheral neuropathy (J Palliat Care 2020): https://doi.org/10.1177/0825859719827589
- Scrambler therapy for chemotherapy neuropathy: a randomized phase II pilot trial (Support Care Cancer 2020): https://doi.org/10.1007/s00520-019-04881-3
- Efficacy of scrambler therapy in chemotherapy-induced peripheral neuropathy: a systematic review of randomized controlled trials (J Egypt Natl Canc Inst 2026): https://doi.org/10.1186/s43046-026-00347-w
- Prevention and Management of Chemotherapy-Induced Peripheral Neuropathy in Survivors of Adult Cancers: ASCO Guideline Update (JCO 2020): https://doi.org/10.1200/JCO.20.01399

## Connected records

- cancers: [Colorectal cancer](https://onco.cc/cancers/colorectal/), [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [Multiple myeloma](https://onco.cc/cancers/multiple-myeloma/)
- fronts: [Devices & Physical Therapies](https://onco.cc/fronts/devices/), [Recovery & Rejuvenation](https://onco.cc/fronts/rejuvenation/), [Supportive Care & Survivorship](https://onco.cc/fronts/supportive-care/)
- technologies: [Acupuncture for chemotherapy-induced neuropathy](https://onco.cc/technologies/acupuncture-chemotherapy-neuropathy/), [Cancer pain management](https://onco.cc/technologies/pain-management/), [Nerve damage from chemotherapy: what recovers, and what helps](https://onco.cc/technologies/cipn-recovery-and-treatment/)
- drugs: [Bortezomib](https://onco.cc/drugs/bortezomib/), [Oxaliplatin](https://onco.cc/drugs/oxaliplatin/), [Paclitaxel / nab-paclitaxel](https://onco.cc/drugs/paclitaxel/)
- terms: [Peripheral neuropathy (chemotherapy-induced)](https://onco.cc/terms/peripheral-neuropathy/), [Placebo](https://onco.cc/terms/placebo/)
- bottlenecks: [Toxicity and quality of life are undervalued](https://onco.cc/bottlenecks/b-toxicity-qol/)

---
JSON: https://onco.cc/api/v1/entities/scrambler-therapy.json