Does Low Ferritin Increase SHBG?
No, low ferritin does not increase SHBG—the opposite relationship exists: lower ferritin levels are associated with lower SHBG levels, not higher ones.
The Evidence on Ferritin and Sex Hormones
The available research demonstrates an inverse relationship between ferritin and sex hormone-binding globulin, meaning they move in the same direction rather than opposite directions:
In a large cross-sectional study of 1,999 Chinese men, serum ferritin levels showed a significant negative correlation with SHBG (R = -0.161, P<0.001), meaning that as ferritin decreased, SHBG also tended to decrease 1
This negative association remained statistically significant even after adjusting for age and alcohol consumption (adjusted R = -0.181, P<0.001), indicating the relationship is independent of these confounding factors 1
The same study found ferritin was negatively associated with total testosterone (R = -0.205, P<0.001) and free testosterone (R = -0.097, P<0.001), suggesting iron status may influence the broader hormonal milieu 1
Clinical Interpretation
The relationship between ferritin and SHBG does not support the hypothesis that low iron stores drive up SHBG levels. Instead, the data suggest:
Lower ferritin correlates with lower SHBG, not elevated SHBG 1
This may reflect shared metabolic or inflammatory influences on both parameters, rather than a direct causal mechanism 1
The clinical significance of this association remains unclear, as the correlation coefficients are modest and the biological mechanism has not been established 1
Important Caveats
The available evidence comes from observational cross-sectional data in men, which cannot establish causation and may not generalize to women or other populations 1
Ferritin is an acute-phase reactant that increases during inflammation, which can confound interpretation of its relationship with hormonal parameters 2, 3
No interventional studies have examined whether correcting iron deficiency (raising ferritin) affects SHBG levels, so the clinical relevance of this association remains speculative 1