Therapy
Tamoxifen lowers Lp(a) by 3.35 mg/dL, with the effect nearly 40% stronger at doses of 20 mg/day or above, updated meta-analysis of RCTs finds (Endocrine 2025)
Original title: The impact of tamoxifen on apolipoproteins and lipoprotein(a) levels: an updated meta-analysis of randomized controlled trials
This updated meta-analysis of randomised controlled trials published through October 2024 examined tamoxifen's effect on apolipoproteins and Lp(a), an area with previously inconsistent evidence. Pooled random-effects analysis found tamoxifen treatment in women significantly increased ApoA-I (weighted mean difference 15.22 mg/dL, 95% CI 6.43-24.01, P = 0.001), decreased ApoB (WMD -9.33 mg/dL, 95% CI -15.46 to -3.19, P = 0.003), and decreased Lp(a) (WMD -3.35 mg/dL, 95% CI -5.78 to -0.91, P = 0.007). Subgroup analysis showed a larger Lp(a) reduction in trials lasting 24 weeks or less (WMD -3.65 mg/dL) and in those using tamoxifen doses of 20 mg/day or above (WMD -4.53 mg/dL). The authors conclude tamoxifen lowers Lp(a) alongside favourable changes in ApoB and ApoA-I, an incidental cardiometabolic effect of a drug primarily used for breast cancer treatment and prevention.
Original abstract
Objective: The existing evidence regarding the impact of tamoxifen on lipoprotein(a) and apolipoproteins remains inconsistent. Therefore, this updated meta-analysis of randomized controlled trials (RCTs) aims to enhance the quality of evidence concerning the effects of tamoxifen on these lipid parameters.
Methods: Eligible RCTs published up to October 2024 were meticulously selected through a comprehensive search. A meta-analysis was then performed using a random-effects model, and results were presented as the weighted mean difference (WMD) with a 95% confidence interval (CI).
Results: Findings from the random-effects model revealed an increase in ApoA-I (WMD: 15.22 mg/dL, 95% CI: 6.43-24.01, P = 0.001), alongside decreases in ApoB (WMD: -9.33 mg/dL, 95% CI: -15.46 to -3.19, P = 0.003) and lipoprotein(a) (WMD: -3.35 mg/dL, 95% CI: -5.78 to -0.91, P = 0.007) levels following tamoxifen treatment in women. Subgroup analyses indicated a more significant reduction in lipoprotein(a) levels in RCTs with a duration of ≤24 weeks (WMD: -3.65 mg/dL) and in studies using tamoxifen doses of ≥20 mg/day (WMD: -4.53 mg/dL).
Conclusion: This meta-analysis provides evidence that tamoxifen leads to a decrease in lipoprotein(a) levels, along with reductions in ApoB and increases in ApoA-I among women.
Summary written by lp-a.org from the published abstract; figures as published. Page updated 18 August 2026. Methods.