What is the decreased efficacy of Nexplanon (etonogrel) in individuals with high Body Mass Index (BMI)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: May 6, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Nexplanon remains highly effective for individuals with higher BMI, with minimal reduction in efficacy compared to those with lower BMI. For people with a BMI over 30, Nexplanon's effectiveness may decrease slightly from its typical effectiveness rate, but this reduction is not clinically significant 1. Unlike some hormonal contraceptives that show substantial decreases in effectiveness with higher BMI, Nexplanon maintains excellent protection against pregnancy across all weight categories. This is because Nexplanon delivers etonogestrel directly into the bloodstream, bypassing digestive absorption issues that can affect oral contraceptives in higher-weight individuals. The implant releases a consistent hormone dose regardless of body size, and its placement in the arm ensures reliable delivery.

Some key points to consider when evaluating the effectiveness of Nexplanon in individuals with higher BMI include:

  • The lack of significant reduction in efficacy with increasing BMI, as noted in studies examining the relationship between body weight and hormonal contraceptive effectiveness 1
  • The consistent hormone dose released by the implant, which is not affected by body size or composition
  • The reliable delivery of the hormone through the implant's placement in the arm, which bypasses potential issues with digestive absorption

While some studies suggest slightly earlier hormone level decreases in the third year of use for those with higher BMI, the contraceptive effect remains strong throughout the approved three-year usage period 1. Healthcare providers generally do not need to recommend early replacement or alternative methods based on BMI alone. Overall, Nexplanon is a highly effective contraceptive option for individuals with higher BMI, and its use should be considered on a case-by-case basis, taking into account individual patient needs and medical history.

From the Research

Effectiveness of Nexplanon in High BMI Individuals

  • The provided studies do not directly address the effectiveness of Nexplanon in individuals with high BMI 2, 3, 4, 5, 6.
  • However, studies on hormonal contraceptives, including implants, suggest that the efficacy of these methods may be unaffected by body mass 3, 4.
  • One study found that body weight was associated with pregnancy in users of the skin patch, but BMI was not 3.
  • Another study found that the efficacy of implants and injectable contraceptives may be unaffected by body mass, but the evidence is limited 3.
  • A review of hormonal contraceptives for overweight or obese women found that the evidence generally did not indicate an association between higher BMI or weight and effectiveness of hormonal contraceptives, but the quality of evidence was considered low 4.

Comparison of Contraceptive Methods

  • A study comparing copper-containing intra-uterine devices with depot progestogens found that the copper IUD was more effective than depot progestogens at preventing pregnancy 5.
  • Another study discussed the use of the levonorgestrel-releasing intrauterine device as emergency contraception, but did not address the effectiveness of Nexplanon in high BMI individuals 6.

Limitations of the Evidence

  • The provided studies do not specifically address the effectiveness of Nexplanon in individuals with high BMI.
  • The evidence on the effectiveness of hormonal contraceptives in overweight or obese women is limited and of low quality 4.
  • Further research is needed to establish the effectiveness of Nexplanon in high BMI individuals 3, 4.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Hormonal contraceptives for contraception in overweight or obese women.

The Cochrane database of systematic reviews, 2016

Research

Copper containing intra-uterine devices versus depot progestogens for contraception.

The Cochrane database of systematic reviews, 2010

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.