A patient came in last fall with a complaint that I hear some version of every single week: "I'm losing my hair and nobody can tell me why." She was 46, had been shedding heavily for about a year, had seen her primary care twice and a dermatologist once, and had been told it was stress, then perimenopause, then to try Rogaine. None of those answers were necessarily wrong. None of them were actually a diagnosis. She had never had a thyroid antibody panel. She had never had a ferritin checked. Her last sex hormone evaluation had been a single estradiol drawn on day 14 of an irregular cycle — uninterpretable. She had been told to live with it because no one had actually done the work to figure out what was driving it.
Hair thinning in women is a symptom, not a diagnosis. It has a finite list of treatable underlying causes, and the only way to figure out which one applies to a specific patient is to actually run the differential. That is what this article walks through — the conditions I am ruling in and ruling out when a patient presents with this complaint, the labs I order, and how I sequence treatment once the picture is clear.
The pattern matters more than the volume
Before I order a single lab, the history and the visual exam tell me which bucket to start with. Hair thinning in women does not present uniformly, and the pattern of loss is one of the most diagnostically useful pieces of information in the entire workup.
Diffuse shedding from the entire scalp — what patients describe as "hair coming out everywhere, in the shower, on my pillow, in my brush" — points toward telogen effluvium. This is a synchronized push of hairs out of the growth phase and into the shed phase, and it is reactive. Something happened ninety to one hundred twenty days before the shed started. The trigger could be a pregnancy, a major illness, a surgery, a crash diet, a new medication, an iron deficit, a thyroid swing, a profound psychological stressor, or COVID. Telogen effluvium is usually self-limited if the trigger is identified and addressed, though it can become chronic when the underlying driver persists.
Thinning concentrated at the part line, the temples, and the crown — with widening of the part and visible scalp showing through — points toward female pattern hair loss, which is the same biological process as androgenetic alopecia in men but with a different pattern of follicular miniaturization. This is genetic in its predisposition and hormonal in its expression, and it tends to progress slowly over years rather than appearing as an acute shed.
Patchy circular bald areas with smooth scalp underneath point toward alopecia areata, an autoimmune process that needs a different workup pathway entirely. Hair loss along the front hairline with skin changes points toward frontal fibrosing alopecia, which is a scarring alopecia that requires urgent dermatologic evaluation because once the follicles are scarred, that hair is not coming back.
Knowing which of these patterns is in front of me before I order labs is what makes the panel useful instead of a fishing expedition.
The differential I am actually working through
When I sit down with a patient describing hair thinning, the differential I am running through includes the following categories, usually in this order of clinical likelihood for a mid-life female patient:
- Iron-insufficient telogen effluvium with ferritin under 40 ng/mL
- Thyroid dysfunction — particularly subclinical hypothyroidism with TSH above 2.5, low-normal T3, or undiagnosed Hashimoto's with positive antibodies
- Perimenopausal or menopausal estrogen and progesterone decline driving accelerated follicular miniaturization
- Female pattern hair loss with elevated DHT activity, sometimes overlapping with PCOS or insulin resistance
- Chronic stress and cortisol dysregulation with downstream effects on the HPA axis
- Vitamin D deficiency under 30 ng/mL contributing to follicular cycling problems
- Medication-induced effluvium — SSRIs, beta-blockers, statins, antihistamines used chronically, certain anticonvulsants, methotrexate, lithium, and others
- Recent significant weight loss, particularly rapid loss on a calorie-deficit protocol
- Inflammatory or autoimmune contributors — Hashimoto's, celiac, lupus, IBD
- Scarring alopecias requiring dermatology referral
Most patients I see have two or three of these going on at once. Multiple contributors is the rule, not the exception, and treating only one of them is the most common reason hair recovery stalls.
What I look for on the lab panel
The lab panel I order for a hair thinning workup is broader than what a typical primary care visit produces. I want ferritin specifically — not just a CBC — and I want it interpreted against the hair-relevant cutoff of 40 to 70 ng/mL, not the anemia-prevention cutoff of 10 to 15. I want a full thyroid panel including TSH, free T3, free T4, reverse T3, and both TPO and thyroglobulin antibodies. A normal TSH alone does not rule out thyroid contribution to hair loss. I see patients with TSH at 3.2, free T3 in the bottom quartile, and positive TPO antibodies who have been told their thyroid is fine for years.
The sex hormone panel needs to be timed correctly in cycling women — day 19 to 21 of a regular cycle, or whenever appropriate for an irregular cycle if pinning the day is impossible. I want estradiol, progesterone, total and free testosterone, DHEA-S, and SHBG. Elevated free testosterone or low SHBG with hair loss in a woman should always prompt an evaluation for PCOS or insulin resistance. Low estradiol and low progesterone in a 46-year-old tell me perimenopause is in the picture even if her cycles are still happening.
I add vitamin D, B12, zinc, and a fasting insulin and HbA1c. I screen for celiac with tTG-IgA in patients with any GI history or unexplained nutrient deficits — undiagnosed celiac is a surprisingly common driver of malabsorption-mediated hair loss, and the patient often has no classic GI symptoms.
Not sure where to start?
The Start Here pathway walks you through the most common entry points and helps you decide which consultation type is the right fit. Five minutes of self-assessment can save you a wrong-direction conversation.
What I look for in the integrated picture: not single outliers, but patterns. A ferritin of 32, a TSH of 2.8, a vitamin D of 26, and an estradiol that is half of what it was three years ago — none of those individual numbers will make a primary care lab flag. Together, they tell a coherent story about a follicle that is being underfed, undersignaled, and underprotected, and the hair loss is the visible output of that combined picture.
How I evaluate the medication list
Medications cause far more hair loss than patients realize, and the list of culprits is long. When I look at a medication list, the ones I am specifically scanning for include SSRIs and SNRIs (fluoxetine, sertraline, escitalopram, venlafaxine, duloxetine), beta-blockers (metoprolol, propranolol), statins, ACE inhibitors, lithium, certain anticonvulsants (valproate especially), methotrexate, allopurinol, certain oral contraceptives — particularly progestin-dominant formulations — and chronic high-dose vitamin A or retinoid use.
If the timeline of the hair loss correlates with the start of one of these medications, that is a meaningful clinical lead. The answer is not always to stop the medication — sometimes the medication is treating something more important than the cosmetic effect — but the conversation has to happen, and sometimes a switch within a class is enough to resolve the issue.
Sequencing treatment once the picture is clear
Once the workup identifies the contributors, treatment sequences in priority order based on what is most addressable and most impactful. For most patients in this clinic, the order looks something like this:
First, fix substrate. Iron repletion to a target ferritin above 70. Vitamin D repletion to above 50. Thyroid optimization if indicated, often in coordination with the patient's prescribing provider or with us taking it over directly. These are inexpensive interventions that produce disproportionate gains because they remove the bottleneck the follicle is operating against.
Second, address the hormonal picture if relevant. Hormone optimization for perimenopausal patients with declining estradiol and progesterone often produces meaningful hair stabilization within three to six months. For male patients with related thinning patterns, men's hormone therapy addresses the testosterone-DHT axis directly.
Third, address the metabolic picture if PCOS, insulin resistance, or significant central adiposity is in play. The metabolic program addresses the insulin and androgen feedback loop that drives follicular miniaturization in this group.
Fourth, regenerative scalp treatment to accelerate follicular recovery once the substrate, hormonal, and metabolic pieces are being addressed. This is where DE|RIVE and PRP-based protocols do their best work — on a follicle that is finally being adequately supported.
Skipping the first three steps and jumping straight to step four is the pattern that produces disappointing results. The follicle has to have what it needs before regenerative treatment can do what it is supposed to do.
When I refer out
Not every hair loss workup ends with treatment in this clinic. The patients I refer out include any patient with evidence of a scarring alopecia (frontal fibrosing, lichen planopilaris, dissecting cellulitis), any patient with patchy alopecia areata that needs immunomodulatory management, and any patient whose workup raises concern for an underlying systemic autoimmune disease that needs rheumatology evaluation. The right answer for those patients is not regenerative treatment in our clinic — it is the appropriate specialist, and I would rather make the referral than treat outside what the data supports.
The concrete next step
If hair thinning is the symptom that brought you here and a real workup has not been done, the comprehensive lab work is where we start. Bring whatever prior labs you have, even if they are several years old — trends matter. Bring your medication list, your supplement list, and a brief written timeline of when the shedding started and what was happening in your life ninety to one hundred twenty days before that. Use the symptom assessment tool before the visit if it helps you organize the picture you want to bring in.
Book a Columbus consultation or a Warner Robins consultation. The first visit gathers the picture and orders the labs. The second visit, about two weeks later, is where we sit with the data and decide what is actually driving this and what to address first. From there the path is usually clear, and most patients leave that second visit with a defined plan that does not depend on guessing.
Medical disclaimer: This article is for educational purposes only and does not constitute medical advice. Individual clinical decisions should be made in consultation with a qualified healthcare provider following appropriate evaluation. References to specific treatments, dosing, or protocols are informational.
Travis spent 17+ years in high-acuity clinical medicine — emergency, cardiac ICU, and cath lab — before founding Revitalize. He is a Certified Platinum Biote hormone therapy provider, the published author of You're Not Broken — You're Unbalanced, and the founder of the Rebuild Metabolic Health Institute. His clinical writing reflects the same precision he brought to critical care: specific, honest, and built around what actually works.
Ready to talk it through with a clinician?
Book online or call either Georgia location. Every visit starts with a consultation.