Pharmacokinetics of Levothyroxine and Factors Influencing Its Therapeutic Efficacy in Hypothyroidism: A Comprehensive Review

Year : 2026 | Volume : 12 | 02 | Page :
    By

    Mohd. Farhan,

  • Nalini Kanta Sahoo,

  • Alex Martin,

  • Rajesh Nath,

  • Asad Jamal Ansari,

  • Ebadurrahman,

  • Saurabh Kumar Chauhan,

  1. M. Pharma Scholar, Faculty of Pharmacy, Rama University, Kanpur, Uttar Pradesh, India
  2. Professor, Faculty of Pharmacy, Rama University, Kanpur, Uttar Pradesh, India
  3. Assistant Professor, Faculty of Pharmacy, Rama University, Kanpur, Uttar Pradesh, India
  4. Assistant Professor, Faculty of Pharmacy, Rama University, Kanpur, Uttar Pradesh, India
  5. Lecturer, Faculty of Pharmacy, Integral University, Lucknow, Uttar Pradesh, India
  6. Lecturer, Faculty of Pharmacy, Integral University, Lucknow, Uttar Pradesh, India
  7. PhD Research Scholar, Department of Pharmacology, School of Pharmaceutical Education and Research (SPER), Jamia Hamdard, New Delhi, India

Abstract

Levothyroxine (LT4) remains the standard therapy for hypothyroidism due to its effectiveness in restoring normal thyroid hormone levels and improving physiological functions. However, its pharmacokinetic profile exhibits considerable variability, which may influence therapeutic outcomes in clinical practice. This review aims to comprehensively evaluate the pharmacokinetics of levothyroxine, including its absorption, distribution, metabolism, and elimination, along with factors affecting its therapeutic efficacy. A structured literature search was conducted using electronic databases, focusing on studies related to levothyroxine pharmacokinetics, drug interactions, and clinical outcomes. Evidence suggests that levothyroxine is primarily absorbed in the small intestine, with bioavailability ranging from 60–80%, and is significantly influenced by gastric pH, food intake, and concomitant medications such as proton pump inhibitors. Differences in absorption and metabolic processes may lead to inadequate therapeutic outcomes even when proper dosing protocols are followed Additionally, levothyroxine therapy plays a crucial role in improving metabolic, cardiovascular, and neuropsychological functions in patients with hypothyroidism. Understanding the pharmacokinetic variability and patient-specific factors is essential for optimizing levothyroxine therapy. Individualized dosing strategies, proper patient counselling, and monitoring of thyroid function are critical to achieving consistent euthyroid status. Future research should focus on improving drug formulations and personalized therapeutic approaches to enhance treatment outcomes.

Keywords: Levothyroxine, pharmacokinetics, hypothyroidism, bioavailability, drug interactions, thyroid hormones

How to cite this article:
Mohd. Farhan, Nalini Kanta Sahoo, Alex Martin, Rajesh Nath, Asad Jamal Ansari, Ebadurrahman, Saurabh Kumar Chauhan. Pharmacokinetics of Levothyroxine and Factors Influencing Its Therapeutic Efficacy in Hypothyroidism: A Comprehensive Review. Research & Reviews: A Journal of Drug Formulation, Development and Production. 2026; 12(02):-.
How to cite this URL:
Mohd. Farhan, Nalini Kanta Sahoo, Alex Martin, Rajesh Nath, Asad Jamal Ansari, Ebadurrahman, Saurabh Kumar Chauhan. Pharmacokinetics of Levothyroxine and Factors Influencing Its Therapeutic Efficacy in Hypothyroidism: A Comprehensive Review. Research & Reviews: A Journal of Drug Formulation, Development and Production. 2026; 12(02):-. Available from: https://journals.stmjournals.com/rrjodfdp/article=2026/view=245902


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Ahead of Print Subscription Review Article
Volume 12
02
Received 08/05/2026
Accepted 11/05/2026
Published 03/06/2026
Publication Time 26 Days
1

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