Chronic pain & Fibromyalgia
Fibromyalgia is the best-studied pain indication for tDCS. Anodal stimulation of the primary motor cortex (M1) is more consistently associated with pain reduction than DLPFC montages.
What the evidence supports
Sham-controlled trials and meta-analyses associate anodal M1 tDCS with reduced pain intensity and improved quality of life in fibromyalgia, as a complementary therapy.
- RCT (Valle et al., 2009; n=41 women with refractory FM): anodal M1 tDCS reduced pain (VAS) in a sustained way up to 60 days (p=0.03); quality of life (FIQ) −28.3% (p=0.0015).
- Meta-analysis (Hou et al., 2016; 16 RCTs, 572 patients): tDCS-subgroup pain effect size 0.568 (95% CI 0.265–0.871); M1 the strongest montage. A more recent meta-analysis (Moshfeghinia 2023): pain reduction SMD −1.55.
- Guidelines diverge: the IFCN (Lefaucheur 2017) assigns Level B (probable efficacy) to anodal left-M1 tDCS, whereas the EAN (2016) considered the evidence inconclusive.
- The DLPFC montage reduced pain immediately, but not durably.
Chronic pain & Fibromyalgia
Strength and limits of the evidence
The guidelines diverge: the EAN (2016, GRADE method) considered tDCS for fibromyalgia inconclusive, whereas the IFCN (Lefaucheur 2017) assigned Level B (probable efficacy) to anodal M1 tDCS — bearing in mind that no indication receives Level A. Recent meta-analyses confirm pain reduction, but Winterholler (2025) stresses that the effects are small and clinical relevance remains uncertain. For spinal cord injury pain, the trials were negative or inconclusive.
Typical montage and dose
Typical montage: anode over M1 (C3) with contralateral supraorbital cathode (more durable benefit); 2 mA, ~20 minutes, 5 to 10 daily sessions.
Safety
Tolerability rated as high by the EAN ("generally excellent"); the main effect is a transient skin reaction under the electrodes, with rare cases of small burns that recover spontaneously.
Sources
- Valle A, et al. J Pain Manag. 2009;2(3):353–361.
- Hou W-H, Wang T-Y, Kang J-H. Rheumatology (Oxford). 2016;55(8):1507–1517.
- Cruccu G, et al. (EAN). Eur J Neurol. 2016;23:1489–1499.
- Lefaucheur J-P, et al. (IFCN). Clin Neurophysiol. 2017;128(1):56–92.
- Moshfeghinia R, et al. BMC Neurol. 2023;23:395.
- Winterholler C, et al. Front Pain Res. 2025;6:1593746.
Informational, non-promissory content. tDCS is a complementary therapy under professional supervision; results vary between individuals.
Other conditions
Depression
Stimulation of the dorsolateral prefrontal cortex (DLPFC) for depressive symptoms, as an evidence-based complementary therapy.
Post-stroke rehabilitation
Adjuvant support to rehabilitation. Recent meta-analyses point to benefit in specific domains — naming (aphasia) and dysphagia; motor function is not established.
Assess your case with a specialist
tDCS indication is individual and must be made by a healthcare professional. Request a no-commitment quote.