Chronic non-specific low back pain (CNSLBP) is a major cause of disability worldwide. Conventional pharmacological treatments offer limited benefits and carry potential risks, prompting interest in alternative approaches, including homeopathy.

The objective of this study was to evaluate the short-term efficacy and safety of a standardised homeopathic biotherapic (Lumbar Vertebra, LM2 potency) for CNSLBP.

A randomised, double-blind, crossover, placebo-controlled clinical trial was conducted with 120 participants diagnosed with CNSLBP. Participants received both the biotherapic and placebo in two treatment phases separated by a washout period. The primary outcome was pain intensity (numeric rating scale); secondary outcomes included functional disability (Oswestry Disability Index), adverse events and use of pain medications. Data were analysed using random effects generalised linear models.

Both the biotherapic and placebo interventions led to significant within-group reductions in pain and disability (p = 0.001 and p < 0.001 respectively). However, no statistically significant differences were observed between the two interventions for either outcome (pain: p = 0.435; disability: p = 0.840). The magnitude of change in pain intensity did not reach the pre-defined minimal clinically important difference (MCID), and mean pain scores at the study endpoint remained above the inclusion threshold. Adverse events were mild and comparable across groups.

No specific effect of the Lumbar Vertebra LM2 biotherapic was demonstrated. Improvements are likely due to non-specific effects such as the therapeutic environment, patient expectations and placebo response. Clinicians should consider the substantial role of non-specific responses in CNSLBP and avoid medications with unfavourable risk–benefit profiles.

The data underpinning the BIOVERT trial findings are available upon request.

The Universidade Federal de São Carlos (São Carlos Federal University) Human Research Ethics Committee approved the BIOVERT protocol (CAAE: 69489123.6.0000.5504—Report 6.207.954, dated July 30, 2023).

Before inclusion, the study's physiotherapist obtained formal consent from each participant via an Informed Consent Form.

• UMIN Clinical Trials Registry (UMIN-CTR)

• ID: UMIN000051957