The exact labs I asked for when my hair was falling out
Published 11 days ago • 19 min read
Hair loss - but not just patching with products!
The Labs I Asked My Doctor For When My Hair Was Falling Out (And What I Actually Did to Fix It)
I have been coaching women (and men) for over a decade, and one thing makes people panic like nothing else: hair loss.
There’s something about pulling a knot out of the drain or seeing the elastic wrap an extra time around your ponytail that hits at a really primal place. I’ve watched women hold it together through very difficult health challenges, and then completely fall apart over a brush full of hair.
I get it, and I’ve been there myself!
This article is a guide of boxes to check off if you’re in it right now.
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(One more thing: This article is for informational purposes only & not a substitute for medical care or consultation).
If you’ve been on the internet looking up hair loss, you’ve probably been told it’s aging, it’s genetics, or you should try supplementing with biotin.
And here’s the thing that none of those things encompass: Most of the time - hair loss is not simply a hair problem. It’s not even really a nutrient problem, although nutrients are part of the story.
Hair loss is a mitochondrial story, a circadian story, and a story about how your cells are making energy, how they’re holding water, and whether the environment around your body (the light you’re under, the rhythm you’re living in, the EMF you’re swimming in, the food you’re eating) is giving your mitochondria what they need to fund the most metabolically expensive tissue your body grows (your hair)
I went through my own full hair journey (no-shampoo years, postpartum texture changes, the drugstore era, the breaking point in 2025, what products I finally landed on) over in this article if you want the personal story. This article is the science and the deeper protocols. The boxes to check, the labs to run, and the order I did things in (not just rushing into buying products).
Why Hair Loss Is Really a Mitochondrial Story
Before I go through the labs, I want you to understand what’s actually happening in your follicles, because once you see it through this lens, everything else makes more sense.
Hair follicles are among the most mitochondrially dense and metabolically active cells in your body. During the growth phase (called anagen), the matrix cells in your follicle divide every 23 to 72 hours [1]. That’s faster than almost any other tissue you have, comparable to bone marrow and the cells lining your gut. Every one of those divisions requires a massive amount of ATP, which means a massive amount of mitochondrial output.
Mitochondria do not make energy out of thin air. They make energy from food, oxygen, water, and light. And they only do it well when their environment is right.
What’s their environment? A huge overlooked part of this is your circadian rhythm.
Mitochondrial function is rhythmic, governed by clock genes that are entrained primarily by light hitting your eyes and your skin [2]. When that rhythm is disrupted (when you’re under artificial light at night, when you don’t see the morning sun, when you eat and sleep on a schedule disconnected from the actual day), your mitochondria can’t optimize their output. They make less energy, more inefficiently, with more oxidative damage as a byproduct.
Photo by Herbert Goetsch on Unsplash
It’s also the water inside your body, and I’m talking about exclusion zone water, or EZ water, also called the fourth phase of water, coined by Dr. Gerald Pollack at the University of Washington.
EZ water is a structured, gel-like form of water that forms next to hydrophilic surfaces, including the mitochondrial membrane [3]. It’s what your mitochondria float in. It’s what allows protons to flow correctly through the electron transport chain. It’s what makes ATP synthesis possible.
EZ water is hugely impacted by infrared light (which is why morning and evening sun - as well as sunlight through the day - matter so much, all are rich in infrared), by grounding, by certain minerals, and by molecular hydrogen. It’s depleted by EMF, dehydration, oxidative stress, and lack of light.
The water you drink isn’t the same as the water your mitochondria actually use & make, and when the conditions aren’t there for it to do that properly (not enough light, not enough minerals & nutrients, too much EMF, too much oxidative stress), your mitochondria run inefficiently. ATP & Water production both drop. The cells that need the most energy (your follicles, your skin, your gut lining, your brain) feel it first.
So when your hair is falling out, the question isn’t really “what nutrient am I missing.” The question is “why are my mitochondria not making enough energy to fund my follicles.” And the answer is almost always some combination of: I’m not getting the right light, my cellular water is depleted, my mitochondria are oxidatively stressed, my circadian rhythm is disrupted, and I’m not feeding my system the building blocks it needs to keep up.
Remember - when it comes to priorties: hair is “expensive” & won’t be a priority if your body thinks you are in danger.
The 90-Day Lag (This Is the Piece Almost Nobody Tells You)
Before we go any further, I need you to understand something about how hair shedding actually works, because it changes how you think about what’s happening to you.
Your hair follicles cycle through three phases. Anagen is the active growth phase, which lasts 2 to 7 years for most healthy hair, and 85 to 90% of your hair is in this phase at any given time. Catagen is a brief 2 to 3 week transition. Telogen is the resting and shedding phase, and it lasts approximately 90 days [4].
This is what I’ve had to explain to many clients: When something stresses your system enough to push a follicle out of the growth phase, the follicle does not shed right then. It moves into catagen, then into telogen, and it sits there for about three months before it actually releases the strand. The new hair growing in behind it is what physically pushes the old one out.
So the hair you found on your pillow this morning or in the drain in the shower last night? The trigger that caused it likely happened around 90 days ago.
This is one of the most well-documented patterns in dermatology. Telogen effluvium “typically develops 2 to 4 months after a triggering event” [5]. The trigger can be a lot of things: a high fever, a surgery, a stressful life event, a crash diet, a hormone shift, a postpartum window, an illness, a medication change, a thyroid hit, a season of caregiving that finally maxed you out. Whatever it was, it happened around three months before you started seeing it in your shower.
This is why almost every woman I work with can’t connect the cause to the effect on her own. By the time the hair is falling, life is often calmer. The crisis is behind her. So she looks at what’s stressful right now and tries to blame that, but that’s typically not it. Look at what was happening in your life 90 days ago. Sometimes 4 to 6 months ago if it was a longer, slower stressor - and that’s where the clues are.
For me, the shedding I noticed in summer 2025 wasn’t about that week or that month. It was the cumulative load of years of caregiving, plus a particularly hard stretch the previous spring, plus a few specific events 3 to 4 months earlier that I hadn’t connected until I sat down and traced it back.
The 90-day lag also works in reverse. When you start fixing the underlying issues, you will not see new growth for 3 to 4 months. The follicles have to finish their telogen rest before they can re-enter the growth phase. This is the part where women quit too early. They change their diet, get the light, start the minerals, and potentially start using new products - and then panic at week 6 because nothing is visibly better yet.
Your hair biology has a timeline, and it is longer than most people realize.
So when you’re in it, two questions matter most. What was happening in your life 3 to 4 months ago? And are you willing to commit to the protocol for at least 4 to 6 months before you decide whether it’s working?
Now the labs.
Photo by National Cancer Institute on Unsplash
The Labs I Asked For & Check Regularly (Screenshot This)
Note: Again reminder that this is not medical advice & I am just sharing my personal experience and what worked for me.
The reference ranges on most labs are designed to flag disease, not to identify the level of function your body actually needs to grow hair, sleep well, or feel like yourself.
A ferritin of 22 will come back marked “normal,” and your hair could potentially keep falling out, because the lab range was built to catch anemia, not to catch the depletion that kills hair growth. You have to know what to ask for, and what the optimal numbers are, not just what’s flagged.
This is the list I brought to my appointment & requested:
Ferritin. The single most important test on this list. Ferritin is your stored iron. Iron is required for the cytochromes in your electron transport chain [6]. Without iron, your mitochondria literally cannot complete the steps that produce ATP. Standard labs flag low ferritin around 10 to 15 ng/mL. For hair growth and proper mitochondrial function, you want to be above 40, ideally 50 to 70 [7, 8]. If your last lab came back saying iron was “fine,” go look at the actual ferritin number, not the flag.
Full thyroid panel. Not just TSH. You need TSH, free T4, free T3, reverse T3, and the antibodies. Your thyroid is the master regulator of mitochondrial output. T3 directly stimulates mitochondrial biogenesis and ATP production [9].
When your body has been chronically stressed or chronically under-eating, it deliberately suppresses T4-to-T3 conversion to save energy [10]. Your TSH can look “normal” while your free T3 is in the basement and your reverse T3 (a decoy that blocks T3 receptors) is climbing.
Hair follicles need active T3 to stay in the growth phase [11]. Without it they go dormant. This is the exact pattern I see in women who’ve been doing “all the right things” for years and still can’t figure out why their hair is thinning.
This is why so many women start having hair loss on keto or carnivore diets -which are notorious for creating a low T3 situation.
Even after being off carnivore for years - my T3 was struggling due to stress & skipping dinner too often (I was looking after my kids…..but started focusing more on eating potassium rich carbs balanced with protein & fat - AND stopped skipping dinner entirely while trying to get my T3 back to the higher end of normal).
Vitamin D (25-hydroxy). Vitamin D is not really a vitamin, it’s a hormone, and you make it from UVB hitting your skin. It’s also a direct signal of your circadian and seasonal alignment. Are you actually outside, in the sun, in the part of the day when the angle of the sun produces UVB? If yes, your vitamin D climbs. If you’re indoors all day, wearing sunglasses, using SPF, your vitamin D tanks. Vitamin D receptors live inside your hair follicles and directly regulate the growth cycle [12]. Most labs flag “sufficient” above 30 ng/mL, but if you are not supplementing - I like to see 40-60.
B12 and folate. Required for methylation and for proper mitochondrial function. Underdiagnosed all the time, especially in women on metformin or acid blockers, or with any gut absorption issue [13]. Below 500 pg/mL for B12 is suboptimal even if not flagged.
But here’s the part most people don’t know: If your B12 or folate comes back too high (which was the case for me), that’s also a problem. High serum levels often mean the nutrient is sitting in your bloodstream and not getting into the cell where it’s supposed to be doing its job.
What you actually want to know is what’s getting into the cell. That’s why I also look at MMA (methylmalonic acid) and homocysteine (mine was on the higher end last summer) alongside B12 and folate. If those are elevated, it tells you the B12 and folate aren’t doing their job at the cellular level, regardless of what the serum number says.
Zinc, copper, and ceruloplasmin. This is the test most doctors won’t think to run and it’s a huge piece. Copper is required for cytochrome c oxidase, which is the final step in your electron transport chain. Without copper your mitochondria literally cannot finish making ATP [14].
But copper has to be bioavailable, which means it has to be bound to ceruloplasmin. Years of supplementing zinc (which lots of women do for skin or immunity) can deplete copper. Depleted copper means depleted ceruloplasmin, which means iron sitting in storage and never reaching the cells. You can have plenty of iron and still be functionally anemic at the mitochondrial level. This is one reason some women take iron forever and never feel better.
Magnesium RBC. Not serum. Magnesium is involved in over 300 enzymatic reactions, including every single step of ATP production. ATP is actually transported and stabilized as Mg-ATP, meaning without magnesium your ATP is useless [15]. Serum magnesium is almost meaningless because your body keeps it stable by pulling magnesium from your bones. RBC tells you what’s actually inside your cells.
A full hormone panel. Estradiol, progesterone, testosterone (free and total), DHEA-S, and a 4-point salivary cortisol. Cortisol is supposed to follow a rhythm tied to light. High in the morning when the sun rises, low at night. When that rhythm inverts (which it does for most stressed-out women under artificial light), everything downstream gets disrupted, including the hair growth cycle [16]. A single morning blood draw misses the entire story.
On the testosterone piece specifically: this is the lab nobody pays enough attention to in women dealing with hair loss. High testosterone, and more specifically the DHT it converts into, is one of the biggest drivers of patterned hair thinning (the crown, the part line, the temples). DHT binds to scalp follicles and gradually miniaturizes them over multiple growth cycles, which is why this kind of loss looks different than telogen effluvium. Telogen effluvium is diffuse, all-over shedding. Androgenic loss is patterned, slow, and shows up as a widening part or thinning at the crown.
If your testosterone is elevated, you need to ask why. Most of the time it’s downstream of something else. The biggest driver can be insulin resistance. High insulin tells your ovaries to make more testosterone and also drops your SHBG, which means more free, active testosterone available to convert into DHT. This is the engine of PCOS-driven hair loss.
Perimenopause is another big one, because as estrogen drops faster than testosterone, the ratio shifts and androgens become proportionally more active. Coming off hormonal birth control is another common trigger, because your ovaries can rebound with an androgen surge for several months.
So when testosterone or free testosterone comes back elevated, that’s not the diagnosis. That’s a symptom. The real question is what’s driving it. Fixing the upstream issue (usually insulin and leptin signaling, sometimes the perimenopause transition, sometimes post-pill rebound) is what actually moves the needle on this kind of hair loss. SHBG is also worth knowing because it tells you how much of the testosterone you have is actually free and active.
Fasting insulin and HbA1c. Subtle blood sugar instability drives cortisol up and pushes follicles into shedding.
Leptin (fasting - 12-14 hours). Almost nobody runs this one. Most doctors don’t think to, and most labs treat it as an obesity research marker, but for hair loss, especially in women who have been dieting, under-eating, doing low-carb, or running on stress, leptin is one of the most useful numbers you can get.
Here’s what to look for. Leptin that’s too low signals that your body thinks it’s in famine. This is the classic chronic dieter pattern, and it’s the one that crashes hair growth, ovulation, libido, and thyroid output. You want to see leptin in the lower-mid normal range, not at the floor. Leptin that’s too high suggests leptin resistance, where your cells aren’t hearing the signal even though it’s there. Both patterns triage your hair the same way, just through different mechanisms. Optimal for most healthy women is roughly 7-10 ng/mL, with the caveat that this varies with body composition and the lab’s specific range (and you want a complete set of labs and symptoms to make a determination - not just one number). Take my Leptin Quiz Here
If your leptin is at the floor and your hair is falling, that is your body telling you it doesn’t believe it has enough fuel coming in to grow hair, no matter what your scale says. If leptin is high and your other markers (insulin, HbA1c, inflammation) are also elevated, you’re looking at the leptin resistance picture, which needs a different intervention. Either way, knowing the number changes the protocol.
The picture that came back made sense once I saw it.
My homocysteine was borderline high (it was at the very high end of “normal”, which was the first red flag). Homocysteine elevates when your methylation cycle isn’t running well, which usually means your B12, folate, or B6 aren’t actually getting into your cells and doing their job.
And speaking of B12, mine came back high. Most people would look at that and think “great, my B12 is fine.” But high serum B12 with elevated homocysteine is actually the opposite signal. It means the B12 was piling up in my blood because it wasn’t getting into my cells. The lock was broken. The nutrient was at the door but not getting in.
My free T3 was at the low end of normal, which combined with the rest of the picture told me my body had been suppressing thyroid conversion. The classic stress and depletion pattern.
My Leptin was also low (I wasn’t surprised at all) - due to too much attention to my kids at dinner - and eating carbs - but still not enough for a proper signal.
My zinc was low, which makes sense given everything else, but it also matters for the methylation conversation because zinc is a cofactor in a lot of those reactions. Low zinc means slower methylation means homocysteine creeping up means B12 not landing. Everything connects.
In other words, my whole system was telling me, in lab form, what my shower drain was already telling me. My mitochondria were running on fumes. The substrates weren’t getting where they needed to go. My body was triaging, and hair was one of the first things it cut.
How I Fixed It
My follicles didn’t die. Telogen effluvium just puts them to sleep [17]. When you give your body the signal that the environment has changed and energy is available again, the follicles have the opportunity to wake back up.
But remember the 90-day lag we talked about. You won’t see new growth for at least 3 to 4 months because the follicles have to finish their telogen rest before they can re-enter anagen. Commit to the protocol and let your body do its thing.
What I Did
A note before I go through this. By the time my hair started falling, I had already been doing the foundational work for many years. Morning sunlight, blue light blocking at night, daily minerals, Quinton, salt, molecular hydrogen for over a year, sauna, grounding, sun exposure during the day & clean water.
That foundation is what kept the situation from being much worse than it was, and it’s what made the targeted fixes work as fast as they did. Without it, the supplements and the food changes would have landed on much thinner soil.
So here’s what I kept doing, and what I added once my labs told me what was really going on.
What I kept doing. Morning sunlight within 15 minutes of waking. Sunset light when I can. Blue blockers at sunset. Amber lights at night. Quinton hypertonic in the mornings. Baja Gold salt in food, and sauna three times a week. Bare feet on the ground when weather allows. Hydrogen inhalation in the evenings and hydrogen water through the day (Axiom, code SARAHK for 15% off). Good quality drinking water, not tap. EMF awareness, phone off body & in another room as much as possible. MyCircadianApp to help guide me with light.
Real dinner every night. This was the biggest single shift for me. I had developed a sneaky habit of skipping dinner or making it really light, especially when I was busy with my kids.
Skipping dinner is one of the worst things you can do for your hair, thyroid, and hormones. Your body needs fuel coming in during the evening to keep cortisol from spiking overnight and to give your thyroid and follicles substrate to work with during overnight repair. So I started actually eating dinner every night. Real protein, real carbs, real fat. (and don’t even get me started on skipping breakfast - that is WORSE!)
More carbs through the day. Carbs support your thyroid, your liver, and your mitochondria. Chronic low-carb eating, especially for perimenopausal women, suppresses T3 conversion. 100 grams of protein a day minimum. No more long gaps between meals & enough fat. This was a mindset shift also & I really had to coach myself that more carbs would not equal weight gain (and I didn’t gain any weight!)
Methylated B vitamins.Active B12.KAL Adenosylcobalamin is the B12 I personally use. Adenosylcobalamin is one of the two active forms of B12 (the other is methylcobalamin), and it's the form that works directly inside your mitochondria to support energy production.
Most B12 supplements use cyanocobalamin, which is a synthetic form your body has to convert before it can use, and a lot of women can't convert it well. The active forms skip that step. Adenosylcobalamin specifically is what your mitochondria use to metabolize fatty acids and certain amino acids into ATP, which is why it tends to give a noticeable energy lift when it lands. I take it as a sublingual tablet first thing in the morning.
For folate, I take Pure Encapsulations Folate 1000, which is L-5-MTHF (Metafolin). This is the active methylated form of folate that your body can use directly without having to convert it. Standard folic acid (which is what most supplements use and what's added to fortified flour) is synthetic, and a lot of women can't methylate it well, especially anyone with an MTHFR variant. The L-5-MTHF skips that conversion step. Within a few months of switching, my homocysteine started coming down.
Zinc with copper built in. I take a zinc carnosine and copper orotate combo, 16 mg zinc to 2 mg copper. Zinc carnosine is one of the more bioavailable forms of zinc and it's also been studied specifically for gut healing, which is a nice bonus. Copper orotate is one of the more absorbable forms of copper. Taking zinc alone for any length of time depletes copper, and depleted copper means iron can't get where it needs to go (which is back to the ceruloplasmin piece I mentioned earlier). The combo keeps the ratio in check while it rebuilds your zinc status. (I use Mitolife code SARAHK)
Boron. 2 mg a day. One of those minerals nobody talks about. Supports magnesium retention, helps with hormone metabolism, and plays a role in bone and connective tissue. (this is the one I use)
Shilajit, religiously. First thing in the morning, dissolved in warm water, small pea-sized amount. Loaded with fulvic acid, humic acid, and trace minerals in a form your body actually absorbs. It supported my mineral status, my adrenals through a really stressful season, and gave me a noticeable energy lift without the crash. (Mitolife Panacea code SARAHK)
Nervous system work. Saying no more. Letting things go. Stopping the relentless self-optimization (which is its own form of stress). Walking outside without a podcast. Cooking without my phone. Slow mornings before work. Real sleep, dark cold room, eight hours.
LAST ON THE LIST!
Hair products that actually worked. I cycled through the no-poo years, every clean brand on the market, the drugstore era, and finally landed on Monat after my friend Dr. Tyna Moore convinced me to try it. Full story (and product links, VIP carts for US, UK, and Canada) in my hair journey article. The short version: I use the MONAT IR Clinical thickening shampoo, conditioner, and hair thinning defense serum and the shedding actually stopped. (you can also buy it on the retail store here).
I have another section to this over on substack - which is the full coaching framework I walk my clients through when they come to me about hair loss. The order I tell them to do things in, the specific protocols for different starting points, the things you’d do if you haven’t been doing the foundation work for years like I have, and the troubleshooting for when things aren’t working. (Click here for the article).
One more note about hair loss. This article isn’t a full list of every reason hair loss can happen. There are other layers I haven’t gone as deep into here, and depending on your situation, one or more of these might be part of your picture too.
There’s a deeper hormone piece. Perimenopause and menopause, low progesterone, undiagnosed thyroid antibodies, or PCOS in a woman who doesn’t know she has it. These all show up in hair loss patterns and they need their own targeted work.
There’s a gut piece. Absorption issues, SIBO, low stomach acid, parasites. Especially relevant if you’ve had a course of antibiotics or a stressful gut event in the last year. You can eat all the right things and still not absorb them if your gut isn’t working.
There’s a heavy metal or toxin burden piece. Mold exposure in the home, mercury from old fillings or fish, glyphosate. These are real, and they tend to show up in hair loss patterns that don’t respond to nutrition and lifestyle work alone.
There’s an autoimmune piece. If you have other signs of autoimmunity (joint pain, brain fog, fatigue beyond what your sleep should explain), get the antibodies checked. Hashimoto’s especially shows up as hair thinning long before TSH starts to move.
If you’ve worked through the foundation and you’re still not seeing changes after 4 to 6 months, one of these is usually the missing piece.
Hope all of this helps & please forward to a friend or family member who might be struggling with hair loss.
Warmly,
Sarah
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