# The Impact of Gender Affirming Hormone Therapy on Pain in Gender Minority Adults

> **NIH NIH R01** · UNIVERSITY OF KANSAS MEDICAL CENTER · 2024 · $654,475

## Abstract

PROJECT SUMMARY
In most chronic pain syndromes there is a 1.5-2 times higher incidence in females compared to males after
puberty, which may in part be due to differences in sex hormone levels and receptors and/or other unknown
mechanisms related to sex and/or gender. Gender-affirming hormone therapy (GHT) is routinely used in
gender minority (GM) persons' gender-affirming medical care. Masculinizing GHT includes the use of
testosterone, whereas feminizing GHT includes estrogen and progesterone, often in conjunction with an anti-
androgen. In 2011, The Institute of Medicine identified GM adults as an understudied population in critical need
of more health-related research. The GM community includes those who identify as transgender men (TGM),
transgender women (TGW), and as non-binary (persons whose gender is not binary). There are only a few
studies on how GHT is related to the presence and severity of pain in GM persons. Previous research has
shown that GM persons have been reported to have an overall greater prevalence of multiple chronic pain
syndromes compared to cisgender persons (persons whose gender corresponds to their sex assigned at birth).
Retrospective and cross-sectional studies have identified that GHT may affect the presence and severity of
chronic pain in the GM population, with masculinizing GHT being potentially associated with improvements in
chronic pain and feminizing GHT with estrogen/progesterone and anti-androgens potentially worsening chronic
pain. We hypothesize that the presence of androgenic hormonal influences is protective against the
development of a specific chronic pain mechanism, nociplastic pain – pain that appears to be driven by the
central nervous system (CNS). The mechanisms that underlie nociplastic pain are not entirely understood, but
it is thought that amplified and/or dysregulated pain and sensory signaling within the CNS plays a substantial
role. Numerous chronic pain syndromes have been identified as primarily nociplastic and include fibromyalgia,
tension headache, and chronic low back pain. These and other pain syndromes often co-occur and are
recognized by the NIH as Chronic Overlapping Pain Conditions (COPCs). A large knowledge gap exists and
thus presents a unique opportunity to study how GHT may influence the presence and severity of pain in GM
persons using a rigorous longitudinal design. Aim 1: To characterize the trajectory of pain and pain-related
symptoms in GM adults taking GHT. Aim 2: To perform quantitative sensory testing (QST) and functional brain
neuroimaging of GM adults undergoing GHT to examine the mechanism(s) that underlie changes in pain and
sensory sensitivity associated with GHT. Aim 3: To perform qualitative studies of how GHT affects gender
affirmation, psychological wellbeing, and the experience of pain. We will perform and communicate results of
these studies using a community-engaged approach. Data from our work will better enable clinicians to inform
GM patients about po...

## Key facts

- **NIH application ID:** 10996421
- **Project number:** 1R01NS135833-01A1
- **Recipient organization:** UNIVERSITY OF KANSAS MEDICAL CENTER
- **Principal Investigator:** Andrea Lynn Chadwick
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $654,475
- **Award type:** 1
- **Project period:** 2024-09-18 → 2029-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10996421

## Citation

> US National Institutes of Health, RePORTER application 10996421, The Impact of Gender Affirming Hormone Therapy on Pain in Gender Minority Adults (1R01NS135833-01A1). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10996421. Licensed CC0.

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