Women of Color: Clinical Trial Gaps Explained

Why are women of color underrepresented in clinical trials?

Women of color are underrepresented in clinical trials — including trials of peptide medicines — because of a layered set of structural, historical, and logistical barriers that researchers are only beginning to measure systematically. A 2025 qualitative study named this directly: women of color in that study reported feeling "seen, heard, and still missing" — acknowledged in diversity rhetoric but absent from actual enrollment numbers.

The study identified several concrete reasons women of color decline or never reach trial participation: distrust built from documented histories of medical exploitation and neglect; scheduling barriers, including trials held during work hours with no childcare support; geographic distance from academic medical centers where most trials run; language barriers in consent forms and study communications; and researchers and staff who did not reflect the communities being studied. These are not personal failings. They are design failures — choices made when trials are built without the communities they claim to study.

The numbers reflect those design failures. A systematic review of hypertension and diabetes trials found that even at Federally Qualified Health Centers — clinics specifically serving underserved populations — women and historically underserved groups remained underrepresented relative to their share of disease burden. Trials were physically located in the right places and still missed the people most affected.

Underrepresentation matters for peptide medicine specifically because peptides interact with hormones, body composition, immune signaling, and metabolic pathways that vary across individuals — and those variations are not randomly distributed across racial and ethnic groups. When women of color are missing from trials, researchers cannot detect whether a peptide works differently, causes different side effects, or requires different monitoring in those populations. The trial did not establish those answers. That gap then travels into prescribing, into labels, and into clinical decisions made without adequate data.

A 2025 FDA drug approval analysis found that sex representation in trials frequently did not match the sex distribution of people actually living with the condition being treated. Racial and ethnic gaps compound that mismatch.

What this means practically: when you read that a peptide was studied in thousands of participants, ask who those participants were. If the trial did not report race, ethnicity, or disaggregated outcomes by group, the evidence base has a gap — and your clinician should know that gap exists before drawing conclusions about your care.

This guide does not provide medical advice. Talk with a qualified clinician about your individual health history, medications, and care decisions.

Which disease areas show the largest enrollment gaps for women?

The largest enrollment gaps for women appear in cardiovascular disease, metabolic conditions, PTSD, and dementia research — and women of color face compounding barriers that make their underrepresentation more severe across nearly every disease area. These gaps matter because a drug tested mostly in one group may not work the same way in another.

Cardiovascular disease and diabetes

A systematic review of trials conducted at Federally Qualified Health Centers found that women and historically underserved populations were consistently underrepresented in hypertension and diabetes studies, even though these conditions affect them at high rates in the communities those centers serve (PMID 42465047). The same review found that enrollment numbers rarely matched the actual disease burden in those populations.

A separate analysis of FDA-approved drugs from 2015 to 2023 confirmed that sex representation in trials frequently did not match indication-specific disease burden — meaning the people most affected by a condition were often least likely to appear in the data used to approve its treatment (PMID 42336860).

PTSD

PTSD trials show a specific and measurable gap. Women develop PTSD at roughly twice the rate of men, yet a study predicting sex differences in enrollment patterns found that trial designs — including eligibility criteria and recruitment strategies — consistently produced male-skewed samples (PMID 42628151). The trial did not establish whether peptide-based or other emerging treatments work equally well across sexes, because the enrollment data to answer that question does not yet exist.

Dementia

Women make up the majority of people living with Alzheimer's disease, but clinical trial populations do not reflect that. A call-to-action paper on atypical Alzheimer's variants noted that recruitment practices exclude many patients whose disease presentation differs from the "typical" profile used to design eligibility criteria — and women are disproportionately affected by those exclusions (PMID 42334062).

Why women of color face steeper gaps

Structural barriers — distrust built from historical research abuses, logistical obstacles like transportation and work schedules, and language access — reduce participation rates for women of color across disease areas (PMID 42635329). These are not personal failures. They are system-level problems that produce data gaps affecting treatment decisions for entire communities.

The evidence base for many medicines is thinner for women than the enrollment numbers alone suggest, and thinner still for women of color and women at specific life stages.

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

How do trial design rules exclude women before recruitment starts?

Trial design rules can exclude women — including women of color — before a single recruitment poster goes up, by building eligibility criteria that systematically filter out people whose biology, life circumstances, or demographics don't match the assumed "standard" participant.

Eligibility criteria are the written rules a trial uses to decide who can join. Researchers write them before recruitment opens, and once locked, those rules shape every enrollment decision that follows. A 2025 analysis found that women of color face layered barriers that begin at this design stage — not just at the clinic door — because criteria written without their input rarely account for the conditions, medications, or caregiving responsibilities common in their lives.

Several specific design choices drive exclusion:

Age cutoffs. Trials for conditions like Alzheimer's disease often cap enrollment at a fixed upper age, which disproportionately removes older women, who carry a higher share of the disease burden. Researchers calling for reform note that atypical presentations — more common in certain demographic groups — go unstudied when age windows are too narrow.

Body size thresholds. Trials frequently exclude participants above a set BMI. Women on average have different body composition than men, and BMI cutoffs interact with race and ethnicity in ways that vary by population, so these rules can quietly remove large groups of women before anyone counts them as "excluded." A meta-analysis of rheumatoid arthritis trials found that BMI-related eligibility rules affected who entered trials and, separately, how well treatments worked across body-size groups — a gap that only becomes visible when the data are broken down after the fact.

Comorbidity exclusions. Rules that bar people with hypertension, diabetes, or both are common. A systematic review of trials at Federally Qualified Health Centers (source) found that women and historically underserved populations — who carry higher rates of these conditions — were underrepresented in exactly the trials designed to study those diseases.

Sex-based assumptions baked into outcome measures. When trials choose measurement tools validated only in male-predominant samples, women's responses may not register accurately. A review of anxiety measures used in dementia trials (source) found that most tools had not been validated for the populations actually enrolled.

By the time a trial opens its doors, the data it will generate may already be incomplete for many women. The trial did not establish answers it was never designed to find.

This content is for general health education only and is not medical advice. Speak with a qualified clinician about your individual health situation.

What did hypertension and diabetes trials at community health centers find?

Hypertension and diabetes trials at community health centers found that women — and women of color specifically — were enrolled at rates that often did not reflect who actually carries the burden of these conditions in the real world. A 2025 systematic review and meta-analysis examined clinical trials conducted at Federally Qualified Health Centers (FQHCs), which are safety-net clinics serving low-income and uninsured patients, and found that representation of women of color in hypertension and diabetes research remained inconsistent and frequently underdocumented.

FQHCs matter because their patient populations skew toward Black, Hispanic, and Indigenous women — groups who carry disproportionately high rates of both hypertension and type 2 diabetes. When trials run at these clinics still fail to enroll or report on these groups adequately, the evidence gap follows the people who need answers most.

The review found three specific problems:

• Women were enrolled in many of these trials, but researchers identified gaps in how race and ethnicity data were collected and reported, making it difficult to assess whether women of color were represented proportionally to their disease burden in the communities served.
• The trials did not establish whether findings from predominantly white or male study populations apply equally to women in this study's target demographic — that question stays open.
• Underreporting of demographic subgroups means clinicians reading these trials cannot always tell whether a treatment worked similarly across different groups of women, or whether the average result masks meaningful differences.

This matters for anyone reading a headline that says a peptide medicine "works" for blood pressure or blood sugar. Works for whom, in which bodies, at which life stages — those details live in the enrollment data, and the review found that data is often missing or incomplete.

A separate analysis of sex representation across FDA-approved drugs from 2015 to 2023 found that women were underrepresented in trials relative to their share of disease burden across multiple conditions, including cardiometabolic ones. That pattern shapes what clinicians know — and what they don't — when they prescribe.

Ask your clinician whether the evidence behind any peptide medicine you're considering included people who share your background, age, and health history. That question is not paranoia. It is exactly what the research says is missing.

This section is not medical advice. It does not replace a conversation with a licensed clinician who knows your individual health history.

Does trial leadership affect who gets enrolled?

Yes, trial leadership affects who gets enrolled — and research on women of color shows the connection is direct, not incidental. When the people designing and running a trial don't reflect the population the medicine is meant to serve, the gaps show up in recruitment, retention, and whose data shapes the final label.

A 2025 analysis of oral and maxillofacial surgery trials found that women held a minority of principal investigator positions. Principal investigators write the eligibility criteria, choose the study sites, and decide which outcomes to measure. Those choices, made before a single participant is enrolled, determine whose biology gets studied.

The pattern extends beyond surgery. A systematic review of hypertension and diabetes trials at Federally Qualified Health Centers (source) found that women in those studies were underrepresented relative to their share of the disease burden — even at clinics specifically designed to serve underserved communities. Proximity to care did not close the gap when trial design hadn't accounted for it.

Eligibility criteria are one mechanism. Broad exclusions — for reproductive age, hormonal contraceptive use, or body weight thresholds — can quietly remove large groups of women before recruitment even begins. A meta-analysis of FDA-approved drugs from 2015 to 2023 found that sex representation in trials frequently did not match the actual disease burden in women, meaning the drugs were approved on data that skewed male.

Site location is another. Research on nonparticipation among women of color identified practical barriers — transportation, work schedules, distrust built from historical exclusion — that trial teams with limited diversity were less likely to anticipate or address. Women in that group cited feeling unseen by research teams as a reason for declining to participate.

A PTSD trial enrollment study found that sex differences in who enrolled were partly predicted by how the condition was framed and measured — suggesting that outcome tools chosen by the research team shaped which patients recognized themselves in the study description.

None of this means a trial led by men produces bad science. Leadership composition is one structural factor, among several, that shapes who gets counted.

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.