Univariate MR analysis of the IVW method showed that TC (IVW, OR: 1.1, 95% CI: 1.02–1.19, p = 0.016), LDL‐C (IVW, OR: 1.12, 95% CI: 1.02–1.22, p = 0.017), apo B (IVW, OR: 1.07, 95% CI: 1.01–1.14, p = 0.019), and apo E (IVW, OR: 1.12, 95% CI: 1–1.24, p = 0.042) were all significantly associated with an increased risk of CFS. This evidence concerns the gene APOB and myalgic encephalomeyelitis/chronic fatigue syndrome.