Hair Health Essentials · Research Programme
Strand 01GLP-1 & Hair Shedding
Characterising hair shedding in GLP-1 medication use
Hair shedding following initiation of GLP-1 receptor agonist therapy is now among the most frequent presentations in our clinic. The published evidence describes its incidence. It does not describe its presentation. This strand establishes a structured clinical framework for characterising it — across nutritional, hormonal, psychological, dermatological and mechanical dimensions — in specialist trichological practice.
Phase 1 · Assessment framework established · Case documentation underway
01 · The Gap
Incidence is documented. Presentation is not.
What exists in the literature is adverse-event tabulation from pharmaceutical trials: how many participants reported hair loss, at what dose, against placebo. Useful, and entirely insufficient for clinical characterisation.
It records that shedding occurred. It does not record when it began relative to the weight-loss trajectory, what the follicles looked like under magnification, what the iron and thyroid status were, whether protein intake had collapsed alongside appetite, whether perimenopause arrived in the same window, or what the scalp itself was doing.
In practice, the medication is rarely the sole variable. It is frequently the trigger that exposes what was already present. Characterising that — systematically, across every contributing dimension — is the work this strand undertakes.
A trial adverse-event table captures one variable. A trichological assessment captures the presentation.
02 · The Framework
Eight dimensions, recorded for every case
The assessment protocol applied across this strand. Each dimension is documented to a consistent standard, producing a structured record rather than a clinical impression.
01
Temporal Mapping
Onset of shedding relative to therapy initiation, dose escalation, and the weight-loss curve. Establishes whether the timeline is consistent with telogen effluvium.
02
Trichoscopy
Follicular and shaft assessment under magnification. Differentiates telogen shedding from miniaturisation and from mechanical breakage — a distinction invisible to patient report.
03
Haematological Status
Ferritin, full blood count, thyroid function. Interpreted against thresholds relevant to follicular function rather than general reference ranges.
04
Nutritional Adequacy
Protein and caloric intake under pharmacological appetite suppression. The follicle is metabolically costly and physiologically non-essential; it is deprioritised early.
05
Psychological Context
Concurrent stressors, the distress attached to visible shedding, and the psychological load of rapid physical change — captured structurally, not anecdotally.
06
Endocrine Context
Perimenopausal transition, postpartum recovery, contraceptive and HRT changes — variables that compound silently within the same clinical window.
07
Scalp Assessment
Inflammation, follicular occlusion, barrier integrity. The cutaneous environment in which regrowth must occur, evaluated independently of the shedding itself.
08
Mechanical History
Chemical services, thermal exposure, traction and product use. Routinely absent from medical review, and routinely contributory.
03 · Evidence Base
What the literature currently establishes
In the pivotal weight-reduction trials, hair loss was reported in 4–5% of participants receiving tirzepatide across dose groups, against 1% on placebo. The sex differential is pronounced: approximately 7% of women, against under 1% of men.
The prescribing information attributes these events to the weight reduction rather than to direct pharmacological action on the follicle. Hair loss is not listed in the semaglutide prescribing information.
The wider literature is not settled. The dominant interpretation is telogen effluvium driven by the magnitude and velocity of weight loss; a minority of reports describe improvement in hair status on these agents, plausibly mediated by improved insulin sensitivity. That divergence is itself an argument for structured clinical characterisation.
Zepbound (tirzepatide) FDA Prescribing Information §6.1, NDA 217806 — pooled SURMOUNT-1 and SURMOUNT-2 data. Verified against the primary label document.
04 · Programme Phase
Where this strand stands
Phase 1
Current
Framework establishment
The assessment protocol is defined and in application. Cases are being documented prospectively to a consistent standard.
Phase 2
Next
Structured analysis
Systematic analysis of the documented record against the eight-dimension framework, under defined methodological governance.
Phase 3
Planned
Peer review
Submission for peer-reviewed publication. No findings will be disseminated in any form prior to that process concluding.
05 · Research Standards
The standards this programme holds to
Findings are not disseminated before peer review
No result, pattern, proportion or outcome from this strand will be published, promoted or implied prior to completion of peer review. Programme phase and methodology are communicated; findings are not.
Descriptive by design
This strand characterises a clinical presentation. It is not constructed to establish causation, and no causal claim is made or will be made from it.
No efficacy claim attaches to this work
The programme is not designed to demonstrate the effectiveness of any product, service or intervention. Spontaneous resolution is characteristic of telogen effluvium and cannot be excluded from any observed course.
Consistency of clinical observation
All clinical assessment within this strand is conducted by a single trichologist applying one method, eliminating inter-observer variability. Assessments are correspondingly not independently verified. Both conditions are stated.
Separation of observation and analysis
Clinical assessment and methodological handling — study design, data structure, anonymisation and reporting — are held separately within the team, as a deliberate safeguard against interpretive bias in practice-based research.
Interests declared in full
This programme is conducted within a commercial trichology practice. The practice and the team hold a commercial interest in trichology services relevant to the population documented. This is declared here and in any submitted manuscript. No external or pharmaceutical funding has been received.
06 · Programme
Active research strands
Strand 01
GLP-1 & Hair Shedding
Phase 1 · Active
Characterising the presentation of hair shedding concurrent with GLP-1 receptor agonist therapy across eight clinical dimensions.
Strand 02
Menopause & Hair
In development
Characterising hair and scalp change across the perimenopausal and postmenopausal transition in specialist trichological practice.
Clinical lead: Clare Devereux, IAT Certified Trichologist. Harley Street, London. Clinics also in Dublin.
This page describes research in progress and is provided for information only. It does not constitute medical advice. Anyone taking GLP-1 medication should keep their prescribing clinician informed of any concerns.
