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Trial Representation: Are Women Studied?

Trial representation gaps mean women are often understudied in drug research. Here's what the latest data shows and why it matters for your health decisions.

Trial representation means how many people from a given group — women, older adults, people of color, people with specific health conditions — were actually enrolled in the clinical trials used to approve a medicine. For peptide medicines and other drugs, that number shapes what the label can and cannot honestly claim about how the drug behaves across different bodies and life stages.

Key takeaways

  • A 2025 Nature Communications analysis of FDA-approved drugs from 2015–2023 found that sex representation in trials frequently does not match the real-world disease burden carried by women.
  • A systematic review of hypertension and diabetes trials at Federally Qualified Health Centers found that women and historically underserved populations were enrolled at rates that did not always reflect their share of the affected population.
  • Qualitative cardiovascular research identified distrust, logistical barriers, and poor community outreach as concrete reasons women and minority patients decline or never reach trial enrollment.
  • Atypical Alzheimer's disease variants—which affect women disproportionately—are frequently excluded from trial designs, leaving a specific evidence gap for that group.
  • Researchers studying cancer trial enrollment identified practical 'bright spot' strategies—flexible scheduling, community navigators, and language-concordant staff—that measurably increased participation from underrepresented groups.

What does trial representation actually mean for women's health?

Trial representation means how many people from a given group — women, older adults, people of color, people with specific health conditions — were actually enrolled in the clinical trials used to approve a medicine. For peptide medicines and other drugs, that number shapes what the label can and cannot honestly claim about how the drug behaves across different bodies and life stages.

When a trial enrolls mostly men, or mostly people of one age range, the data generated reflects that group. A 2025 systematic review examining FDA-approved drugs from 2015 to 2023 found that sex representation in trials frequently did not match the actual disease burden in women — meaning women in this study carried a larger share of certain conditions than their share of trial enrollment. Sex-based differences in hormone levels, body composition, kidney function, and metabolism can all affect how a peptide is absorbed, processed, and cleared from the body, which makes that gap consequential.

When women are underenrolled, the trial did not establish whether the drug's effects, side-effect profile, or effective dose range apply equally to women. The label reports what the enrolled population experienced. If that population skewed male or skewed toward a narrow age range, the label's safety and efficacy data reflects that skew. Subgroup analyses — where researchers break out results by sex after the fact — can hint at differences, but a subgroup is rarely large enough to draw firm conclusions.

Representation also varies by who leads the research. A 2025 analysis of oral and maxillofacial surgery trials found gender disparities in trial leadership, and leadership shapes study design, including which outcomes get measured and which populations get prioritized for enrollment.

Life stage adds another layer. A trial that enrolled women aged 30–55 tells you almost nothing about how a peptide behaves in a woman aged 70, or in someone who has recently gone through menopause, or in an adolescent. These are biologically distinct populations, and collapsing them into a single "women" category erases clinically meaningful differences.

Barriers to enrollment compound the problem. Qualitative research on cardiovascular trials found that distrust of research institutions, logistical burdens like transportation and childcare, and poor communication about trial risks all reduce participation from groups already underrepresented — which means the data gap tends to widen over time without deliberate effort to close it.

Ask your clinician whether women were well-represented in the trials for a medicine you're considering, and at what life stage. The honest answer is sometimes "we don't fully know," and that uncertainty deserves to be named, not papered over.


This content is for general health education only and is not medical advice. Consult a qualified healthcare provider before making any decisions about medicines or treatments.

Which disease areas show the biggest sex gaps in FDA trial data?

Trial representation gaps in FDA data are largest — and most consequential — in cardiovascular disease, metabolic conditions, and neurology, where women have been consistently enrolled at lower rates than their share of disease burden would justify.

A 2025 analysis of FDA-approved drugs from 2015 to 2023 mapped sex representation in trials against the actual proportion of each disease that affects women in the population. That study found that women were underrepresented relative to disease burden in cardiovascular indications: the women enrolled in those trials made up a smaller slice of participants than the slice of cardiovascular patients who are women in the real world. Cardiovascular drugs—including peptide-based therapies targeting metabolic pathways—may behave differently across sexes in ways the trial data cannot yet confirm or rule out.

Cardiovascular disease. Women carry a substantial share of hypertension and related disease burden, yet a systematic review of hypertension and diabetes trials found that women and historically underserved groups were underrepresented in clinical trials at Federally Qualified Health Centers. The review covered enrollment patterns, not outcomes—so the question of whether results apply equally remains open.

Metabolic conditions including diabetes. The same systematic review identified diabetes trials as another area where enrollment did not reflect the population seeking care. Peptide medicines used in metabolic contexts sit directly in this gap.

Neurology and dementia. Women develop Alzheimer's disease at higher rates than men, yet a call to action on atypical Alzheimer's variants identified significant gaps in trial design and inclusion criteria that limit what researchers can conclude about diverse patient groups—including women in this study at different life stages.

Cardiovascular research participation broadly. A qualitative study of patient perspectives found that barriers to cardiovascular trial participation—including distrust, logistical obstacles, and poor outreach—fell disproportionately on groups already underrepresented in the data.

When a drug label reports efficacy, that result reflects the people who were actually enrolled. If women in a given study made up 30% of participants but 55% of patients with that condition, the label's numbers describe a trial population that skews male. Clinicians and patients reading those labels are working with incomplete information—not wrong information, but information with known limits.


This section is for general health education only and does not constitute medical advice. Consult a qualified healthcare provider before making any treatment decisions.

Why are women and underserved groups still missing from so many trials?

Trial representation of women and underserved groups remains uneven across medical research, and that gap directly shapes what clinicians know—and don't know—about how peptide medicines behave in different bodies. This is not a new problem, and it is not close to solved.

A 2025 systematic review and meta-analysis examining hypertension and diabetes trials at Federally Qualified Health Centers found that historically underserved populations were consistently underrepresented, even in community-based settings designed to reach them. Diabetes and hypertension are two of the conditions for which peptide-based medicines are most commonly studied. When the people most affected by a disease are missing from the trials testing its treatments, the resulting data carries blind spots.

Several forces drive this pattern:

  • Eligibility criteria written around a "default" patient profile—often a middle-aged man without comorbidities—can quietly exclude people who are pregnant, postmenopausal, or managing multiple conditions at once.
  • Logistical barriers including transportation, childcare, inflexible work schedules, and language access fall harder on lower-income participants. A qualitative cardiovascular study found that patients named distrust of research institutions and practical scheduling conflicts as the two most common reasons they declined to enroll.
  • Who leads the research shapes who gets studied. A review of oral and maxillofacial surgery trials documented a persistent gender gap in trial leadership—and leadership influences study design, recruitment targets, and which outcomes get measured.
  • Sex-disaggregated reporting remains inconsistent. A cross-sectional analysis of FDA-approved drugs from 2015 to 2023 (source) found that sex representation in trials varied substantially by disease indication, and that enrollment numbers alone don't tell you whether researchers analyzed results separately by sex.

When a drug label reports efficacy data, that data may come from a trial population that did not include people with the same biology, life stage, or health history as the person reading it. The label reports what the trial established—nothing more.

Research on cancer trial recruitment identified concrete strategies that increased participation from underrepresented groups: community partnerships, flexible visit scheduling, and patient navigators who speak participants' languages. These approaches work. They are not yet standard.

Gaps in representation are not a reason to avoid evidence-based care. They are a reason to ask your clinician which populations a specific trial enrolled—and what the label does and does not say about people like you.


This content is for general health education only and does not constitute medical advice. Consult a qualified healthcare provider before making any decisions about your care.

How does poor trial representation affect Alzheimer's and dementia research for women?

Poor trial representation directly shapes what researchers know — and don't know — about how Alzheimer's disease and dementia progress differently across women's lives, and gaps in that knowledge affect every treatment decision made downstream.

Alzheimer's disease affects women at higher rates than men, yet the clinical trials that generate evidence about treatments have not consistently enrolled women in numbers that match that disease burden. A 2025 analysis of FDA-approved drugs found that sex representation in trials frequently did not align with the sex-specific burden of the disease being studied — meaning the people most affected were not always the people most studied — sex representation in FDA trials. Drug metabolism, symptom presentation, and disease progression can differ by biological sex, so findings from a male-skewed trial may not translate cleanly to women.

The problem compounds in Alzheimer's specifically. A 2025 call to action on atypical Alzheimer's variants pointed out that trial designs often exclude people with less common disease presentations, which are disproportionately diagnosed later in life — a life stage where women make up a larger share of patients atypical Alzheimer's trial design. Excluding those patients narrows the evidence base further.

Measuring how women in these studies actually experience dementia is another weak point. A systematic review of anxiety outcome measures used in dementia trials found that the tools researchers chose were rarely validated specifically for people living with dementia, raising questions about whether the data captured what patients genuinely felt anxiety PROMs in dementia trials. Imprecise measurement tools produce imprecise results, regardless of enrollment numbers.

Barriers to enrollment make the gap harder to close. Research on cardiovascular trials identified that distrust of medical institutions, logistical burdens, and poor communication about trial risks all reduce participation among groups already underrepresented in research cardiovascular trial barriers. Those same barriers appear across disease areas and likely affect Alzheimer's trial enrollment too, though dementia-specific data remain limited.

When a clinician or caregiver reads a study about a peptide medicine being investigated for cognitive decline, the evidence behind it may come primarily from trials that did not include enough older women, did not use measurement tools validated for that population, or did not report results broken down by sex. The label may report findings from a mixed population without specifying what women in that study experienced separately.


This section is for general health education only and is not medical advice. Speak with a qualified clinician about any treatment decisions.

What strategies have actually improved enrollment of underrepresented patients?

Several concrete strategies have improved trial representation of underrepresented patients. The evidence points to a short list of approaches that actually move enrollment numbers rather than just intentions. The gains are real but uneven, and no single fix works across every setting or population.

What the research found works

Trust emerged as the single most cited barrier to enrollment in a qualitative study of cardiovascular research participants — not logistics, not language, not time. Patient Perspectives in Cardiovascular Research found that patients who enrolled through community-based organizations or trusted clinicians were far more likely to complete trials than those recruited through cold outreach. A known face reduces perceived risk.

A "bright spots" analysis of cancer clinical trials catalogued specific tactics used by sites that outperformed national diversity benchmarks. Strategies for enhancing participation identified these as the most consistently effective:

  • Embedding research staff inside community clinics rather than academic medical centers
  • Offering transportation reimbursement and flexible scheduling
  • Translating consent documents into patients' primary languages before recruitment began, not after
  • Training site staff to discuss trial participation without assuming patients had prior research literacy

Federally Qualified Health Centers (FQHCs) — clinics that receive federal funding to serve low-income and uninsured patients — showed measurably higher enrollment of historically underserved groups when trials were conducted on-site. A systematic review and meta-analysis found that FQHC-based trials enrolled higher proportions of women and racial and ethnic minority patients compared with trials run exclusively at academic hospitals, though the authors noted that data quality across included studies varied.

Where the evidence gets thin

Knowing a strategy works at one site does not mean it scales. Patient Perspectives in Cardiovascular Research noted that trust-building takes time that short trial timelines rarely budget for. The bright spots analysis acknowledged that high-performing sites often had institutional champions — individual researchers or administrators who prioritized diversity — and that structural conditions, not just tactics, drove results.

Atypical patient populations face a separate layer of barriers. A call to action on atypical Alzheimer's variants noted that trials rarely design inclusion criteria broad enough to capture patients who present differently from the "typical" case, which systematically excludes younger patients and those with less common symptom profiles regardless of outreach efforts.

The strategies above describe what worked for specific groups in specific studies. They are not a guarantee of what any individual will experience in a trial setting.


This section is for general health education only and is not medical advice. Speak with a qualified clinician about your own care.

What should women ask before trusting a drug's evidence base?

Before trusting any drug's evidence base, women deserve clear answers to four questions about clinical trial representation, sex-specific data, who led the research, and what the label actually reports versus what remains unknown.

Who was in the trial — and in what numbers?

A trial can enroll women and still tell you almost nothing useful about them if they make up only a small fraction of participants. A 2025 systematic review examining FDA-approved drugs from 2015 to 2023 found that sex representation in trials frequently did not match the real-world disease burden in women. Ask specifically: what percentage of participants were women, and were results analyzed separately by sex? Without sex-disaggregated analysis, the trial cannot confirm the drug behaves the same way in women's bodies as in men's.

Were results broken down by life stage or reproductive status?

Women are not a single biological category. A 50-year-old postmenopausal woman and a 28-year-old woman of reproductive age may respond to the same peptide medicine differently — and most trials do not separate these groups. Research on cardiovascular trial participation found that patients themselves identified this kind of granular representation as a core trust issue. Check whether the trial distinguished participants by age, menopausal status, or other life-stage factors. If it did not, the evidence gap is real.

Who designed and led the study?

Trial design shapes which questions get asked. A 2025 analysis of research leadership in oral and maxillofacial surgery (source) documented persistent gender disparities among principal investigators — a pattern seen across medical fields. Studies led by more diverse teams are more likely to build in sex-disaggregated analysis from the start. Ask whether the research team included women in leadership roles and whether a sex-and-gender analysis plan was pre-registered.

What does the label actually say — and what does it leave out?

Drug labels report what trials established, not what is theoretically possible. If a label says a drug was studied in adults without specifying sex breakdown, that absence is informative. A cross-sectional analysis of AI clinical trial consent disclosures (source) found that gaps in what trials formally disclose often go unnoticed by patients. Read the label's clinical studies section directly, or ask a clinician to walk through it with you.

Gaps in evidence are not a reason to panic. They are a reason to ask better questions — and to expect better answers.


This content is for general health information only and does not constitute medical advice. Consult a qualified healthcare provider before making any decisions about medicines or treatments.

Frequently asked questions

What is trial representation and why does it matter for women?
Trial representation refers to how closely the sex, age, race, and other characteristics of study participants match the people who actually have the disease being treated. When women are underrepresented, drug safety and dosing data may not apply to them as accurately as it does to the groups that dominated the trial.
Did FDA-approved drugs from 2015–2023 include enough women in trials?
A 2025 Nature Communications study (PMID 42336860) found that sex representation in trials for FDA-approved drugs frequently did not align with the real-world disease burden carried by women. The mismatch varied by therapeutic area, with some fields performing worse than others.
Are women enrolled fairly in hypertension and diabetes trials?
A systematic review and meta-analysis of trials conducted at Federally Qualified Health Centers (PMID 42465047) found that women and historically underserved populations were not always enrolled at rates matching their share of the affected population. The authors called for targeted recruitment strategies to close this gap.
Why do women decline or miss out on clinical trial enrollment?
A qualitative study of cardiovascular research participants (PMID 42283075) identified distrust of the medical system, scheduling conflicts, lack of transportation, and inadequate community outreach as concrete barriers. These are structural problems, not individual failures.
How does trial representation affect Alzheimer's research specific to women?
A 2025 call-to-action paper in Alzheimer's & Dementia (PMID 42334062) noted that atypical Alzheimer's variants—which disproportionately affect certain groups including women—are routinely excluded from trial designs. This leaves clinicians with little evidence to guide treatment for those patients.
What has actually worked to get more underrepresented patients into cancer trials?
A BMC Cancer review of 'bright spot' programs (PMID 42288829) found that flexible appointment scheduling, community patient navigators, and language-concordant staff measurably increased enrollment from underrepresented groups. These are replicable, low-tech fixes that many trial sites have not yet adopted.
Does research leadership gender affect which patients get studied?
A 2025 analysis in the International Journal of Oral and Maxillofacial Surgery (PMID 42362425) documented persistent gender disparities in who leads clinical trials in that surgical field. Research leadership composition can influence study design, recruitment priorities, and which populations are treated as the default.
What questions should I ask my doctor about a drug's trial data?
Ask whether the pivotal trials included women in numbers proportional to the disease's real-world sex distribution, and whether the published results were broken down by sex. If the answer is no, that is a known evidence gap—not a reason to avoid the drug, but a reason to discuss uncertainty with your provider. This article is for general information and is not medical advice. Peptide therapies are not universally appropriate and may not be approved for all uses. Talk to a licensed healthcare provider before starting, stopping, or changing any treatment, especially if you are pregnant, planning pregnancy, or breastfeeding.
Published 2026-08-20

Medical disclaimer: Her Health Peptides publishes educational, source-linked summaries. We do not provide individualized medical advice, diagnosis, or treatment recommendations. Always talk with a licensed clinician about your specific situation, especially if you are pregnant, breastfeeding, planning pregnancy, or taking other medicines.

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