Guides
Hair Loss, Thinning Hair and Low Body Temperature: What Dr. Wilson Has Written
October 14, 2026 · Wilson's T3 Editorial
If your hair is thinning or falling out, your thyroid tests are normal, and you also run cold or tired, Dr. Wilson’s writing says the next thing to check is your body temperature. His view is that a body under stress cuts back on tissues it can spare, hair first among them, and that some people stay stuck that way. This guide collects what he and the site’s other writers have published on hair, in their words, and says plainly what kind of evidence each claim rests on.
What hair loss looks like, in Dr. Wilson’s book
The symptom chapter of his book describes the pattern he saw in patients, and the moment most people first notice it:
These patients frequently experience hair loss to some degree, especially from the head, but they can lose hair from sites all over the body. Thinning of the lateral one-third of the eye brows is a classic sign of decreased thyroid system function. Patients may also lose their eye lashes, leg hair, and even pubic hair. Most patients with Wilson’s Temperature Syndrome that experience hair loss notice generalized hair loss, especially from the top of their head, near their hair line, and on the sides of the head also (at the temples). Their hair may become so thin that one can often see their scalp. It is usually first noticed as hair on the pillow in the morning or clogging the shower drain. Everyone knows that losing some hair from day to day is normal. But they often notice a significant increase in the amount of hair being lost each day, especially when it comes out seemingly by the handfuls as one passes one’s fingers through one’s hair.
— Dry Hair, Hair Loss, the book
Two things in that passage are worth separating. The outer-eyebrow sign is one he calls “classic” for low thyroid function generally. The rest is a description of what his patients reported, not a test that tells one cause of hair loss from another.
Why he thinks the body cuts back on hair first
His explanation starts with something most people have seen: hair falling out a few months after a serious illness or an operation. From a 2010 article:
You probably know, or can easily imagine, that people often lose excessive amounts of hair within months of severe illness, accident, or major surgery. This is one of the ways our bodies cope with stress. It only makes sense that the body would conserve energy on less vital functions (like skin, fingernail, and hair production) in order to be able to expend more energy on more vital functions (like healing and surviving).
But what if there was a condition where people’s bodies sometimes remain stuck in “conservation mode” and continue to have problems with hair loss and poor hair growth even after the stress has passed? As it turns out there is such a condition and it’s called Wilson’s Temperature Syndrome.
The book makes the same argument at more length, in the chapter on weight. It explains why hair, skin and nails are the first complaints rather than sight or hearing:
It is interesting that the body chooses the most expendable tissues to sacrifice under periods of stress to ensure the survival of the organism. For this reason these patients will first complain of dry skin, decreased hair growth, brittle hair, hair loss, peeling and splitting fingernails, thin eyebrows, decreased sex drive, etc., as opposed to functions more vital for survival, such as vision, hearing, heart and muscle function, etc.
— Weight Gain, Inappropriate, the book
And in a short 2012 article he puts it in one line:
In WTS, as the metabolism slows the body conserves energy by cutting down on expendable functions that are not absolutely necessary for survival – like hair growth. Dry hair, brittle hair, or even hair loss are common symptoms of WTS.
“It only makes sense” and “what if there was a condition” are the language of an argument, not a measurement. The idea is his model of why a low temperature and thin hair turn up together.
Dry, brittle hair and perms that will not hold
Hair loss is not the only hair complaint he describes. The same symptom chapter covers texture:
Dry hair is a common complaint and can include the hair shafts breaking off at the ends. As mentioned in a previous chapter, hair manageability and luster can begin to return within two weeks of beginning proper thyroid hormone therapy, suggesting that the condition of the hair is greatly dependent on the oils secreted by the scalp and not just the composition of the hair shafts themselves.
— Dry Hair, Hair Loss, the book
And one detail that many readers recognise from the salon chair:
Patients also notice that with the onset of Wilson’s Temperature Syndrome, their hair may not hold a perm as well as it used to. They may find that the perm will only hold for a couple of weeks, when previously it would hold for several months. Sometimes their hair will not take a perm at all. Interestingly, most hair dressers are already quite aware of the correlation between decreased thyroid system function and the patient’s ability to maintain a hair permanent.
— Dry Hair, Hair Loss, the book
The treatment chapter adds why he thought these “cosmetic” complaints belonged in a medical book at all:
Even though these are cosmetic issues, they deserve to be mentioned because of the impact that they can have on a patient’s life, financially and emotionally.
— How the Symptoms Are Typically Treated, the book
The case in his book, and his own caution about it
The book reports one patient in particular:
One such patient had noticed a 50% decrease in the amount of hair present on her head. This thinning of her hair had been persistent for several years. With proper liothyronine treatment, the 50% loss of hair was restored, giving her back her full head of hair.
— Dry Hair, Hair Loss, the book
When he retold the same case in 2012, he added the caveat himself:
While this is obviously an isolated case that may not apply to everyone, it suggests that by normalizing body temp, we may optimize metabolism – escaping “conservation mode” and enabling the body to direct energy towards the otherwise expendable task of growing lustrous, healthy hair.
“An isolated case that may not apply to everyone” is the right way to read it, and those are his words.
How long regrowth takes, and why it can go backwards
This is the part people most want to know, and the site is more cautious here than anywhere else on hair. Dr. Wilson’s 2010 article warns that hair can keep falling out even while the temperature is being corrected:
To be sure, recovery upon normalization of body temperature can sometimes be miraculous (just like when any problem is solved). However, we’re talking about balancing an imbalanced system. Can you see how balancing an imbalanced system can be a little unbalanced? Meaning, a system is not balanced until it’s balanced. In the meantime, it’s unbalanced. When systems are unbalanced hair loss can continue. Thus, people sometimes continue having trouble with their hair loss even while their temperatures are being normalized. Some people’s hair doesn’t start growing back until their temperatures are normal and they are off treatment for a while!
A 2013 article by Ginni, one of the site’s writers, gives a time range and explains the setbacks:
Many of the patients who are treated adequately with T3, alone or in combination with T4, see a significant improvement in their symptoms in a few weeks to a few months. However, it can take 3 to 10 months for normal hair growth to resume. Treating hair loss can be a little tricky and sometimes discouraging because patients often experience ups and downs during T3 therapy on their way to overall and sustained improvement. The downs might only be a few days out of a month, but that can sometimes be enough to lose some of the hair that’s been regrowing.
— Thinning Hair? Check Your Body Temperature
That range is the article’s own figure, given without a source. Treat it as the site’s experience, not a measured result.
Other causes the site itself names
Nothing on the site claims that every case of thinning hair comes from a low temperature. Dr. Wilson’s own article lists other causes in the same breath:
The connection between thyroid and hair loss is well known. When the thyroid system becomes unbalanced, either going high or low, hair loss can result. Female hormone imbalances can also result in hair loss. And under stress there can be big changes in the adrenal hormones. Thus, whenever the body is thrown into imbalance, hair loss can result.
Ginni’s article names autoimmune thyroid disease, and the clue the site uses to tell which hair loss might be temperature-related:
Autoimmune thyroid disease can lead to low body temperatures and hair loss, and thyroid antibodies can often be found with blood tests.
If the hair loss comes on during stress with other symptoms of low body temperature such as fatigue, itchiness, depression, insomnia, hives, PMS, trouble concentrating, and so on, it is more likely that the hair loss is related to the low temperatures and other symptoms.
Other causes of both thyroid dysfunction and hair loss can include adrenal exhaustion and nutritional deficiencies.
— Thinning Hair? Check Your Body Temperature
Hair loss in patches, or hair loss with no other symptoms, does not fit that clue. That is a reason to see a doctor about other causes first, and the site’s guide on Hashimoto’s and low body temperature covers the antibody tests.
What patients have usually tried already
The book notes the usual treatments, including the one many people with thinning hair are offered:
Patients will often wear wigs or toupees due to hair loss.
— How the Symptoms Are Typically Treated, the book
Cortisone therapy can often be quite useful in the treatment of arthritis, asthma, and hair loss (frequently given by injection into the scalp). However, sometimes these problems can respond much better to thyroid hormone therapy than to cortisone therapy as can the other related symptoms of Wilson’s Temperature Syndrome.
— How the Symptoms Are Typically Treated, the book
He calls cortisone “quite useful” and says thyroid treatment “sometimes” does better. That is not advice to stop a scalp treatment, and this guide does not give it. On vitamins, he writes:
Patients with decreased thyroid system function (DTSF) often find their symptoms to be improved with vitamin supplementation. These patients will frequently respond even better to concurrently treating the underlying problem with proper thyroid hormone treatment.
Two letters the site has published
Readers wrote in, and the 2010 article printed their letters. Each is one person’s account in their own words. Nobody else can check the details.
I have at least two inches hair growth when it hasn’t grown since more than five years ago. I have baby hair growth along my entire hair line and can see more standing up throughout the top of my head.
— Rhonda W., a reader’s letter printed in Thyroid and Hair Loss
My hair was thinning for about 6 months before it finally gave up and just fell out all together. I would lose four or five handfuls in the shower every morning.
Once I cut it all off and started on the T3 therapy, plus the change to a high protein/low carb diet, it started growing like crazy.
— Beth, a reader’s letter printed in Thyroid and Hair Loss
Notice that Beth changed two things at once, her treatment and her diet. A letter like hers cannot say which one did what.
Where each claim comes from
| Claim | Source on this site | Who wrote it | What kind of evidence |
|---|---|---|---|
| Hair loss here is the body saving energy on “expendable” tissue | Thyroid and Hair Loss (2010); the book | Dr. Wilson | A model he argues for; not measured |
| Thinning of the outer third of the eyebrows is a classic low-thyroid sign | Dry Hair, Hair Loss (the book) | Dr. Wilson | His clinical description |
| Dry hair can improve within two weeks of treatment | The book, two chapters | Dr. Wilson | Clinical observation |
| A patient’s 50% hair loss was restored | The book; WTS Hair Symptoms (2012) | Dr. Wilson | One case, which he calls “isolated” |
| Regrowth can take 3 to 10 months, with setbacks | Thinning Hair? (2013) | Ginni, a site writer | Stated without a source |
| Hair grew back on T3 | Two reader letters | Patients | Testimony; one also changed her diet |
What this does and does not establish
It establishes what Dr. Wilson believes and how he reasons: that a body under stress can stay in a low-temperature “conservation mode”, that hair is one of the first things it cuts, and that in his practice correcting the temperature was followed by better hair. It establishes that the site’s own writers expect regrowth to be slow and uneven, and say so. It does not establish that low body temperature causes hair loss, that T3 makes hair grow back, or how often it does. The 2013 article lists four published papers; going by their titles, they look at links between hair loss and thyroid conditions, not at T3 treatment for hair. No trial of the protocol for hair loss has been done. The objection hub sets out why the American Thyroid Association and others do not recognise the diagnosis at all, and that applies to the hair claims as much as to any other.
If you want to act on it
The site’s first step is the same for hair as for everything else:
If you have hair loss you owe it to yourself to start checking your body temperatures
Ginni’s article gives the method and the threshold the site uses, quoted so the numbers stay hers:
A low temperature, typically below 97.8 F, is more than enough to explain low thyroid symptoms or symptoms of a slow metabolism. For the most accurate results, use a liquid metal thermometer, take it three times a day, starting three hours after you wake up, for several days, and average the temperature for each day.
— Thinning Hair? Check Your Body Temperature
The full method is in how to take your temperature for a log, and what the numbers mean is in Dr. Wilson’s words. Medicine is not always the first move, in his account:
Some people are able to gain their health back again by getting their own temperatures back up with diet, exercise, stress reduction, and rest.
What he suggests trying first is collected in before T3. If the log runs low, the next step is a doctor who will look at the log and the hair loss together. The guide to finding such a doctor and the practitioner directory are the starting points. Other symptoms the site treats the same way are gathered under body temperature.
Questions people ask
Can a low body temperature cause hair loss?
Dr. Wilson’s position is that it can, and that the body is saving energy on hair when it runs cold. In his words:
Low body temperatures are more than enough to explain hair loss and low body temperatures can often be corrected.
That is his conclusion from practice. It has not been tested in a trial.
Do thin outer eyebrows mean a thyroid problem?
The book calls it a classic sign of low thyroid function, not a sign specific to Wilson’s Temperature Syndrome:
Thinning of the lateral one-third of the eye brows is a classic sign of decreased thyroid system function.
— Dry Hair, Hair Loss, the book
It is a reason to get checked, not a diagnosis.
Will my hair grow back if my temperature is corrected?
The site does not promise it. Dr. Wilson writes that hair loss can continue while the temperature is being corrected, and sometimes only stops after treatment ends. The site’s 2013 article puts normal regrowth at months, not weeks. The letters printed on the site describe hair growing back. They are testimony, not a result anyone can count on.
Is there a study of T3 therapy for hair loss?
Not on this site, and none is cited here. The hair material is a physician’s model, one case he calls isolated, a site writer’s time estimate, and two reader letters.
This is a reader’s guide compiled from the writing published on this site. Every quotation is verbatim, links to its source, and is attributed to the person who wrote it. It is not medical advice, and nothing here should change a prescription or a treatment without the doctor who gave it.