ContextPre-diabetes is a significant public health problem worldwide. India has a very high rate of progression from pre-diabetes to diabetes, 75–78 per thousand persons per year. ObjectiveTo study the efficacy of individualized homeopathic medicinal products (HMPs) against placebos in preventing the progression from pre-diabetes to diabetes. DesignSix-month, double-blind, randomized (1:1), two parallel arms, placebo-controlled trial. SettingOutpatient departments of D. N. De Homoeopathic Medical College and Hospital, Kolkata, West Bengal, India. PatientsSixty participants with pre-diabetes. InterventionsVerum: HMPs plus yoga therapy (YT; n = 30); control: identical-looking placebos plus YT (n = 30). Main outcome measuresThe primary efficacy endpoint was the proportion of participants progressing from pre-diabetes to diabetes, measured after three and six months. Secondary outcomes comprised of fasting blood glucose (FBS), oral glucose tolerance test (OGTT), glycated hemoglobin percentage (HbA1c%), lipid profile, liver enzymes (alanine transaminase, aspartate transaminase), urea and creatinine, and Measure Yourself Medical Outcome Profile version 2 (MYMOP-2); all measured after 3 and 6 months. ResultsThe proportion of participants converted from pre-diabetics to diabetics (n/N; n = diabetics, N = prediabetics) was significantly less in the verum group than control: HbA1C% (month 3: verum – 2/30 versus control – 11/30, p = 0.003; month 6: 3/30 vs. 2/30, p = 0.008), OGTT (month 3: 0/30 vs. 8/30, p = 0.015; month 6: 0/30 vs. 1/30, p = 0.008), but not according to FBS (month 3: 1/30 vs. 1/30, p = 0.779; month 6: 1/30 vs. 3/30, p = 0.469). Several secondary outcomes also revealed significant improvements in the verum group than in placebo: HbA1C% (p < 0.001), OGTT (p = 0.001), serum ALT (p = 0.031), creatinine (p = 0.012), and MYMOP-2 profile scores (p < 0.001). Sulphur, Bryonia alba, and Thuja occidentalis were the most frequently indicated medicines. Thus, HMPs outperformed placebos by successfully preventing the progression of pre-diabetes to diabetes. Trial registrationClinical Trials Registry – India CTRI/2022/04/042,026; UTN: U1111–1277–0021