Do you have low T?

If you google “low testosterone” you’ll see lots of ads for testosterone replacement.  Some are from pharmaceutical companies that sell testosterone, others from obvious snake-oil salesmen.

Both types of ads list vague sets of symptoms, encourage you to believe that they are pathologic, and want to sell you something to make you better.  For example, the pharmaceutical company Solvay gives you a handy guide for speaking to your doctor, and a quiz to see if you have “low T”.  The quiz asks some questions that may be useful, but also asks very general questions about your sense of well being, and includes this gem:

I don’t feel sick, I just don’t feel like myself anymore. Could I have Low T?

The ad then gives this advice:

Because Low T signs and symptoms may not be clear and apparent, they may seem to be a normal part of aging or assumed to be caused by other health conditions. But talk to your doctor if you have symptoms of Low T. And ask to get tested. All it takes is a simple blood test that can be done during a routine checkup. If you do have Low T, your doctor may recommend treatments that can help bring testosterone up to normal levels and keep them there.

If you have diabetes, you should ask your doctor for a Low T test. The Endocrine Society recommends that all men with type 2 diabetes have their testosterone levels checked. Patients who have been diagnosed with diabetes have an increased chance of also having Low T.

Let’s step back for a moment.  What is being claimed is that low testosterone levels in males is a common cause of certain symptoms, and that testosterone replacement therapy can alleviate these symptoms.  To evaluate this claim from the perspective of science-based medicine, we need to ask specific questions.

  1. Is there a plausible connection between testosterone levels and certain symptoms?
  2. What is a normal testosterone level?
  3. Are there specific symptoms that correlate with lower levels?
  4. Does replacement therapy correct these symptoms?

Testosterone is an important hormone in males, and the effects of complete testosterone deprivation are easily observed.  Castration has different effects on males depending on whether it is done before puberty or after.  Given the effect of total androgen (testosterone) deprivation, it is plausible that partial deficiency may lead to physiologic problems.

Defining normal testosterone levels is problematic though.  Most studies show a decline in testosterone levels with age.  What is “normal” at 30 is not “normal” at 70.  Does this decline correlate with symptoms?

Decline in testosterone level with age

Decline in testosterone level with age

The answer isn’t clear.  Studies have shown that low testosterone levels are associated with different symptoms at different ages.  In older men with sexual dysfunction, low testosterone levels were associated with severe erectile dysfunction and decreased frequency of intercourse.  In younger men, low testosterone levels were associated with a decrease in nocturnal erections and reduced libido.  In the middle of the studied age  range, there were no significant associations between testosterone levels and sexual symptoms.  What this may tell us is that in older men, low levels of testosterone likely contribute to severe symptoms of sexual dysfunction.

The answer to question 2 is that normal testosterone levels vary with age, the type of test used, and the time of day the blood is drawn. Testosterone decreases with age, and this decrease correlates with certain symptoms.    Because of these and other data, the recommendation of the Endocrine Society (the most comprehensive and authoritative source) is to restrict the diagnosis of testosterone deficiency to men who have consistent symptoms and an unequivocally low testosterone level.

Question 3 has a difficult answer.  As we’ve seen, in certain age groups, certain sexual symptoms correlate well with low T levels.   There are some weak associations between less specific symptoms and testosterone deficiency (symptoms such as fatigue, loss of vigor, depressed mood, decreased physical performance).  Most of these less specific symptoms can be caused by a variety of problems or by none at all.

So, the data support a connection between certain symptoms and low testosterone levels.  Can testosterone replacement therapy (TRT) improve these symptoms?

The evidence is mixed.  There seems to be good evidence that testosterone replacement improves libido, but has little effect on erectile dysfunction (especially in younger patients).  There is a paucity of placebo-controlled studies of TRT, but non-placebo-controlled trials show some improvements in energy and sense of well-being.

Several medical conditions are correlated with low T. Obesity fairly strongly correlated with low testosterone levels, but there are no consistent data that show an improvement in obesity with TRT.

In sum, testosterone deficiency is a real problem that may affect a small but significant number of men.  The symptoms most consistent with low T are sexual problems, especially with age.  Replacement therapy seems to help with these symptoms in some men.  The ads for testosterone replacement therapy are, in my opinion, very problematic, nearing the point of deception.  They seem to link all manner of vague and common symptoms to low T, and imply that the use of their product is likely to fix these problems.   These ads explicitly instruct patients to ask for testing that may not actually be required. They shift the focus from a careful, methodical analysis of a difficult problem to frank disease mongering, encouraging the pathologizing of what may be normal symptoms, and offering up a costly therapy that may be no better than placebo, but with additional risk.


Corona, G., Mannucci, E., Ricca, V., Lotti, F., Boddi, V., Bandini, E., Balercia, G., Forti, G., & Maggi, M. (2009). The age-related decline of testosterone is associated with different specific symptoms and signs in patients with sexual dysfunction International Journal of Andrology, 32 (6), 720-728 DOI: 10.1111/j.1365-2605.2009.00952.x

Spetz, A., Palmefors, L., Skobe, R., Str??mstedt, M., Fredriksson, M., Theodorsson, E., & Hammar, M. (2007). Testosterone correlated to symptoms of partial androgen deficiency in aging men (PADAM) in an elderly Swedish population Menopause, PAP DOI: 10.1097/gme.0b013e318057786b

Allan, C., Forbes, E., Strauss, B., & McLachlan, R. (2008). Testosterone therapy increases sexual desire in ageing men with low–normal testosterone levels and symptoms of androgen deficiency International Journal of Impotence Research, 20 (4), 396-401 DOI: 10.1038/ijir.2008.22

Reyes-Vallejo, L., Lazarou, S., & Morgentaler, A. (2007). Subjective Sexual Response to Testosterone Replacement Therapy Based on Initial Serum Levels of Total Testosterone The Journal of Sexual Medicine, 4 (6), 1757-1762 DOI: 10.1111/j.1743-6109.2006.00381.x

Bhasin S, Cunningham GR, Hayes FJ, Matsumoto AM, Snyder PJ, Swerdloff RS, Montori VM, & Task Force, Endocrine Society (2010). Testosterone therapy in men with androgen deficiency syndromes: an Endocrine Society clinical practice guideline. The Journal of clinical endocrinology and metabolism, 95 (6), 2536-59 PMID: 20525905

Araujo, A., Esche, G., Kupelian, V., O’Donnell, A., Travison, T., Williams, R., Clark, R., & McKinlay, J. (2007). Prevalence of Symptomatic Androgen Deficiency in Men Journal of Clinical Endocrinology & Metabolism, 92 (11), 4241-4247 DOI: 10.1210/jc.2007-1245

Posted in: Science and Medicine

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20 thoughts on “Do you have low T?

  1. Scott says:

    There is a paucity of placebo-controlled studies of TRT, but non-placebo-controlled trials show some improvements in energy and sense of well-being.

    It seems worth highlighting that energy and sense of well-being (or lack thereof) are symptoms that are likely to be particularly susceptible to placebo effects. So such evidence is even less convincing than if they had shown, say, an increase in nocturnal erections.

  2. kvanh says:

    Anytime they make up a slang sounding nickname like “T” for a drug or hormone I pretty much assume it’s a scam.

  3. Antiboty says:

    I work with a lot of young “athletes” (read: gym rats) who often diagnose themselves with low testosterone due to their inability to put on muscle despite years of weightlifting and smashing back whey protein shakes. From personal discussions as well as reading many fitness forums on the internet, they actively seek out doctors that basically guide them to the right set of signs that would signify low test and thus receive steroids for free, basically.

  4. windriven says:

    Here in Seattle we have one Dr. Gerald Mixon, a family practice MD who runs something called the Longevity Medical Clinic. He advertises widely on the radio (and maybe TV – I don’t have one so I don’t know). I have never met Dr. Mixon but am skeptical given the tenor of his advertising. And I offer this from his web site:

    “Over the last 25 years, the testosterone level of the average American man has decreased by about 24%. This is almost a 1% per year average decline. We are not just becoming a feminist nation; we are becoming a feminized nation. The reason for this overall decline in male hormone levels is poorly understood, but I suspect that it is related to the widespread presence of estrogenic compounds in our society. Many of the plastics and preservatives used in our day-to-day products and foods have an estrogen like effect on the body. ”

    He goes on to wax rhapsodic about male virility. I’m reminded of Gen. Bat Guano and his precious bodily fluids.

    Hormone replacement schemes – absent clear and compelling evidence for the benefits and broad understanding of the risks strikes me as plain stupid. No one should forget the image of the dying, 43 year-old Lyle Alzado on the cover of SI. Alzado was among the first of professional athletes to admit using anabolic steroids to improve performance. He went to his grave blaming them for the brain tumor that killed him. RIP.

  5. Peter Lipson says:

    Male hypogonadism is real. But scammers and quacks are all over this stuff.

    There is definitely a misogynist vibe to a lot of the stuff out there. Some of the “longevity” docs and other testosterone pushers make it sound like you aren’t a real man, and even give drugs that suppress what little estrogen you may have in your body, just to make sure all the girliness is purged.

  6. That was quick.

    I saw a Low T advertisement two nights ago on TV and thought of SBM.

  7. Chris says:

    windriven, Bastyr is just across the lake from Seattle. Of course there are lots of quacks. I often find myself yelling at the car radio for the wonky ads from the Super Supplement store to the cancer place with naturapathic oncologists… though I missed the Mixon ads.

    Hmmm…. looked him, up. He has a radio show Saturday morning. I don’t listen to that station. If I do listen to talk radio on Saturday morning it is the gardening with Cisco (and I really miss the foodie show on Saturday evenings with Tom Douglas and Thierry Rautureau).

  8. windriven says:


    I haven’t heard his radio show but ad I heard got my woo antenna fully erect ;-)

  9. Chris says:

    Maybe it is selective bias. I really don’t have to worry about testosterone, since I really don’t want to shave facial hair (I lack a Y-chromosome). If I heard them, I probably ignored them.

  10. oderb says:

    Most seriously a recent small study showed an increase in morbidity and mortality – significant enough to halt the study- with the use of Testim among post 75 year old men. I can’t find the abstract but here’s a law firm’s take on the study….

  11. Joe says:

    @windriven on 07 Oct 2010 at 5:39 pm

    That wasn’t Bat Guano (who was only a major and didn’t carry loose change into combat) it was Gen. Jack Ripper.

  12. windriven says:

    Thanks Joe, you’re right. Jack D Ripper, brilliantly portrayed by Sterling Hayden.

  13. jeremywhiner says:


    Lyle Azado was falsely accusing testosterone of causing his brain tumor. As far as I know, there is no direct correlation between the two (someone please prove me wrong on this if that’s the case). His own physician clearly and repeatedly stated that anabolic androgenic steroid usage (AAS) was not responsible for his death.

    Moreover, you’re comparing apples to oranges — hormone replacement therapies are typically rather low dosages, and are not at all the same thing as true anabolic usage for something like muscle or strength gain. They typically also use your basic AAS — testosterone, in some form, plain and simple — athletes typically “stack” things like testosterone with items that benefit you athletically — testosterone by itself isn’t really that effective for muscle gain or strength/speed, so it’s usually used in conjunction with compounds that benefit those particular aspects.

    I’ve known many people that have used recreational (read: dangerously high, hazardous to your health) levels of AAS. I myself have never used them. I also know a few people that receive HRT/TRT, and your standard dosage (from a responsible doctor, albeit perhaps a doctor easily swayed by woo) isn’t enough to give you any real muscular or strength benefit. It’s not going to change a wimpy mid-20s kid into Arnold, and it’s not going to turn a 60 year old into Jack LaLanne. As you’ve all noted — it’s largely placebos.

  14. jeremywhiner says:

    And to be clear, I’m not claiming that toying with your hormones isn’t dangerous. It definitely is — you can screw up your body’s homeostasis pretty quickly, and it’s relatively permanent.

    And AAS can have lethal effects — serious heart problems, high cholesterol (which is basically inevitable with long term use), the obvious hypogonadism (which is usually controlled with other pharmaceuticals), so on and so forth. So I’m not attempting to tout the health benefits, just trying to clarify the difference between a “pharmaceutical protocol” that a professional athlete would use, compared to a “therapy dose” that you should/would receive from any doctor.

  15. Jim Laidler says:

    I’ve seen the TV commercial about “Low T” – in it, they claim that decreased energy, lack of “enjoyment” and low sex drive could be signs of “Low T” and that – surprise! – there’s a treatment for it (just ask your doctor). If I remember correctly, the ad was sponsored by Solvay, the makers of Androgel.

    I have to admit that my very first thought when I heard the term “Low T” was that this was a scam. My second thought – once I realized that the ad was too glossy to be the typical scammer – was that I missed the days when prescription pharmaceuticals weren’t advertised to the general public. This looks too much like a company trying to create the perception of a widespread but underdiagnosed disease simply to sell their product.

    How long, I wonder, before there are questionable doctors telling their male patients that even though their testosterone level is within the normal range, it is “on the low side” – that they have “subclinical low T” and would feel better if they were taking testosterone?

    Solvay’s “Low T” website claims that in the US over 13 million men over age 45 have “Low T”. According to the US Census Bureau, there were 53.5 million men over age 45 in the US (as of their July 2010 estimate). This would mean – if we are to believe Solvay’s figure – that nearly a quarter (24.3%) of men over 45 have “Low T”.

    That figure seems a little high. I wonder where they came up with it – the literature don’t seem to support that high a number.

    On the other hand, if their goal is to convince men “of a certain age” that they need a drug – their drug – to treat their flagging energy, sagging spirits and floppy libido….well, those sort of numbers are just the thing!

    Jim Laidler

  16. I’m not surprised at reports of increased well-being with testosterone supplementation. I think it’s not uncommon for transmen to abuse testosterone supplements because it’s so goddamn much fun. Feelings of invincibility! Bouncing off the walls! Libido that will do anything that moves!

  17. For a not scientific but interesting cultural look at testtosterone, This American Life did an episode on it awhile back.

  18. delaneypa says:

    “Obesity fairly strongly correlated with low testosterone levels”.

    Small technical point: Obesity does lower TOTAL testosterone (something about aromatization from fat cells), but does not affect FREE testosterone, which is the physiologically active part. Most of the men on testosterone I inherited in my practice are overweight, of which most have normal free testosterone levels without replacement and felt the same when testosterone was discontinued (disclaimer: anecdotal data).

  19. kestrel says:

    Careful! By addressing this deceptive, direct to consumer drug campaign, you may create an expectation that you will also tackle the hundreds of other iterations just like it! You would need a whole new website and i encourage you to do just that. lawlz, as the kids say…

    My favorite “T” study was presented at a CEU conference and although the details are vague now (do i have low T?) it described a component of the study that tested the walking ability and grasping ability (measured by ability to stand up from a chair and walk to a door and open it) of octogenarians+ who were basically taking T to improve their quality of life. It led to something like a 40% increase in the activity vs. the control ( i forget how the quantified it ). No negative side effects were reported.. besides anecdotal reports of the T supplementation (in this case injections or transdermal i forget) causing suspected latent cases of cancer to blossom… dunno how

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