Table 1.

Assessment of instrument strength on major exposures of interest for the two-sample MR analyses

Phenotype	unit measurement	Using all variants as SNP instruments			Using only variants associated with exposure at p < 1e-5 in indep. subset		Reference
		F-stat	nSNPs	Prop. of variance explained	nSNPs	Prop. of variance explained
Male pattern baldness (MPB)	per SD change in self-reported MPB score	1800.72	473	0.140	287	0.123	–
Total testosterone (totalT)	per SD change in measured endogenous total testosterone	981.79	174	0.081	117	0.074	Ruth et al.
Predicted free testosterone (freeT)	per SD change in derived endogenous free testosterone	576.95	101	0.049	78	0.047	Ruth et al.
Sex hormone-binding globulin (SHBG)	per SD change in measured endogenous SHBG	1880.57	274	0.145	266	0.144	Ruth et al.

nSNPs refer to the total number of variants considered in the MR analyses after the harmonisation process. F-stat refers to the F-statistics of the association between the combined SNP instrument and the exposure (phenotype) of interest. See supplementary Data 1 for the individual SNP effect estimates for each exposure of interest.