Figure 1 Effects of testosterone on a man’s body
Testosterone is the fuel for a man’s engine. It’s the primary hormone responsible for all things male. It strengthens your muscles and bones, puts hair on your chest (but not your head), and plays an important role in sexual performance. Testosterone can boost desire and it can cure depression. It can make you stronger, better, faster—then again, it may do nothing of the sort if you don’t actually need it. Beware: Many men are lured to seek testosterone when, in fact, they absolutely do not need it. On the other hand, if they need it and don’t get it they may suffer from worsening obesity, diabetes, hypertension, heart disease, and ultimately, early death.
Testosterone is made in the testicles and surges during puberty, but as men get older, it can dwindle down. Many men don’t realize they are running low because unlike a car’s gas tank, there is no “empty” warning light for the T tank. Although you can’t help aging and it’s certainly better than the alternative, there are a number of things you can do to keep your testosterone from running out too soon. Poor lifestyle choices including overeating, lack of exercise, lack of sleep, abuse of drugs and alcohol, and unmanaged stress can all siphon T out of your tank. There are other causes too that you may not be able to control, including medical conditions and necessary medications. But the good news is there are ways to fill ’er up no matter what the cause.
Unlike most medications, testosterone is not taken as a pill, but there are a variety of simple options from injections to implants to creams. Many supplements claim to boost T but almost never do. Many men get T from friends or trainers, often with bad consequences. The Internet is filled with “recipes” for guys to follow to self-medicate. Many testosterone clinics have sprouted up with less than fully trained personnel running the show. T should always be prescribed by a doctor who is knowledgeable about it because the consequences of taking it can be very serious, including sterility, erectile dysfunction, blood clots, and even cancer. When properly prescribed and monitored, however, the benefits of T for guys who need it far outweigh the risks.
Wouldn’t it be great if we had some sort of dashboard for our bodies to let us know when there was trouble brewing? Instead we have to pay close attention to how we feel and look out for telltale signs and symptoms. There are a few key warning signs that you may be running on empty. One of the most common is low libido, which means low sexual desire. This can sneak up on you. You might still be able to have erections, but it doesn’t occur to you to use them anymore. Perhaps your partner is starting to complain that the only thing that’s getting turned on in the bedroom is the TV. Sexual desire is complicated. Sights, sounds, smells, and touch can all trigger it. So can thoughts and fantasies. But nothing happens if the testosterone is too low. Testosterone turns just another pretty face into a burning object of desire. When it comes to sex, testosterone is lubricant for the brain—without it, the gears of lust come grinding to a halt.
Testosterone works on both “brains.” The penis actually needs normal levels of testosterone for erections to work properly. Studies in rats indicate that nerves that carry the signal to the penis shrink in size and drop their signals when T runs low.1, 2 Studies on rabbits indicate the very chambers that fill up with blood during the erection, known as the corpora cavernosa, may become shrunken, stiff, and leaky without normal levels of testosterone as the normal stretchy, smooth muscles that line the blood vessels in the chambers die off and are replaced with fat cells and collagen fibers. Like the rabbits’, your fatty can get fatty but not so fat.3
Sex isn’t all there is to life, but low testosterone also robs you of other important aspects of your life. A very common symptom of low testosterone is fatigue. This is easy to write off as due to working hard, which so many of us do. All work and no play makes Jack a dull boy, but sometimes it’s because Jack doesn’t have enough testosterone to be able to play after a full day of work. In the case of low T, you may find yourself dozing off in your easy chair soon after dinner, night after night.
Low T clouds your focus and concentration. You may feel you have just “lost your edge” because you are “tired out from work” or because you are “getting older.” The truth may be that your brain is running low on the testosterone it needs to stay sharp and focused. Restoring T may be just what it takes to get back your mental stride, stay focused, and be productive. In some cases, it’s more serious than just being on top of your game. Low testosterone can result in clinical depression in some men, and correcting it can part the clouds, eliminating the need for prescription antidepressants for many.
Low T actually makes you weaker. It makes your muscles shrink and makes it harder to lose excess fat—even if you work out. A clue to low T may be diminishing returns at the gym, or unwanted weight gain despite dieting. Seventy percent of men with low T are obese.4
Your bones get weak too, but you may not notice that until it’s too late—or you start losing height as your spine compresses. Your skin can also get weaker, becoming dry and flaky, and you might start to lose body hair. Even your immune system may get weaker.
Low T increases your risk of diabetes, bad (LDL) cholesterol, high blood pressure, and heart disease. This deadly combination is now known as “metabolic syndrome.” You can throw obesity into the mix too: At least half of men with diabetes have low T, and having low T doubles your risk of getting diabetes. The lower your T, the higher your blood pressure and the worse your bad cholesterol tends to be.5
You may not have any symptoms until it’s too late and you are stricken with a heart attack or stroke. If left untreated, low T results in a shorter life span. You don’t want your first clue that you have low T to be your last clue, so if any of these signs or symptoms is ringing a bell, get checked out.
Going to the doctor with these various complaints can be embarrassing for you and overwhelming for her, so a handy survey was put together that boils all the moaning and groaning down into a score that alerts the doctor as to whether further testing is in order. The survey is cleverly named ADAM, which stands for Androgen Deficiency in the Aging Male (see Table 1).
A positive questionnaire result is defined as a “yes” answer to questions 1 or 7 or any three other questions.6 This cues the doctor to consider ordering some blood tests to check your testosterone levels.
Even the blood tests for testosterone are tricky because testosterone can be measured in different ways by different labs, and they don’t all match up with each other. It’s like having different referees, each with different rulebooks, ruling on the same play. Fortunately, the results are close enough in most situations. In some cases, your testosterone number may be in the normal range, but it’s not working normally in your body. This can happen because a lot of the testosterone floating around your bloodstream is actually stuck on protein molecules, where it can’t do anything for you. If there are too many of these proteins, the “normal” level of testosterone will actually be too low, and you will suffer the consequences. There are ways to measure these proteins, called sex hormone binding globulin (SHBG) and albumin, and then calculate the amount of “free” testosterone floating around in your blood to determine if you are okay or not. Sometimes even if your total T number is a little low, if the amount of SHBG is low too, then you may be doing just fine with the amount of T that’s floating around free in your blood.
1. Do you have a decrease in libido (sex drive)?
2. Do you have a lack of energy?
3. Do you have a decrease in strength and/or endurance?
4. Have you lost height?
5. Have you noticed a decrease in “enjoyment of life”?
6. Are you sad and/or grumpy?
7. Are your erections less strong?
8. Have you noted a recent deterioration in your ability to play sports?
9. Are you falling asleep after dinner?
10. Has there been a recent deterioration in your work performance?
Even if you account for the types of testosterone and the types of tests, your body will make more or less testosterone depending on the time of day. You tend to make more in the morning because the pituitary gland sends out more LH (luteinizing hormone) signals in the morning, but this can vary, so at least 25 percent of men with low T in one blood test will have normal T in another.7 Most experts recommend checking at least twice, and maybe three times, and always in the morning.
So what is a normal level? Good question. This has been the subject of a lot of debate amongst experts. Probably the best rule of thumb is if your total T is less than 200 nanograms per deciliter (ng/dl) and you have signs or symptoms, then you are too low. Normal T ranges from 400 to 1,000 ng/dl, and it will tend to be higher in young guys and lower in middle-aged men. This is not an absolute, and there are plenty of younger guys with T levels below 400 who are completely normal, so symptoms are key. The real fun comes when a guy’s level is between 200 and 400 ng/dl—now what? Many experts feel that being above 300 ng/dl is the real cutoff for normal, and as long as there are no symptoms, there’s usually no problem. On the other hand, we can do a deeper dive and check the free testosterone. If the free T is normal and the guy doesn’t have symptoms, he is doing just fine. In other cases, T is in the gray zone and the guy does have some symptoms. Then, the best next test is actually having him try testosterone and seeing if he gets better or not. These numbers all have to be taken in the context of the bigger picture of overall health and medical history. I have seen countless guys who were convinced their T must be low when it was in fact normal or even high, and I have seen just as many who have no problem whatsoever with T levels in the gray zone.
Low T can almost always be treated, but it’s important to know why you have it to decide the best treatment. Quick lesson on how testosterone is made: The testicles have special cells, called Leydig cells, that make testosterone. There are a limited number of these cells in the testicles. Leydig cells get turned on and off by signals from the brain, specifically from the pituitary gland. This gland releases a hormone called luteinizing hormone or LH (mentioned earlier), which stimulates the Leydig cells to make testosterone. The testosterone then gets into the circulation and eventually flows back to the pituitary gland. The pituitary gland will keep pumping out LH to try to crank up testosterone production until a “normal” amount starts floating by it. The pituitary is like the annoying child in the backseat of the car on a long road trip asking “Are we there yet?” Once the level of T in the circulation reaches “normal,” the pituitary stops pumping out as much of the LH signal.
Figure 1 Effects of testosterone on a man’s body
Figure 2 Regulation of testosterone production
Some causes of low T are reversible, but others are not. You can control what you put in your mouth. There’s really no food that boosts your T level, but excess fat lowers testosterone.
Testosterone undergoes a chemical reaction in fat cells, which turns some of it into female hormones called estrogens. The fatter you are, the more your testosterone gets turned into estrogen. Fatty man boobs can become real boobs after a while. To make matters worse, the increased estrogens shut down the pituitary gland. So instead of kicking in with more LH signals when T levels drop, the pituitary gland doesn’t react, and your testosterone gets lower still.
For every 4 to 5 kilograms/square meter increase in BMI, testosterone drops the equivalent of 10 years of aging.8 Over half of obese men have low T.9
Another risk of poor diet is developing type 2 diabetes. One in three men in the United States will develop diabetes. If you have diabetes, you have a 50 percent chance of having low testosterone.10 If you have diabetes and you are obese, your chances of having low T are greater than 80 percent! Throw in high blood pressure11 or bad cholesterol (both of which about one-third of guys have)12 and you are sailing into the perfect storm known as metabolic syndrome where your chances of having a heart attack, stroke, or some other cardiac problem are 350 percent higher.13 Please, put down the fork!
Another thing you can control is your use of drugs and alcohol. Excess alcohol can cause liver damage, and this can result in overproduction of sex hormone binding globulin, that protein that sticks to testosterone and keeps it from working. Chronic marijuana use also lowers testosterone by messing with the pituitary gland. Heroin, methadone, and even pain pills with narcotics all can eventually shut down the pituitary gland and consequently switch off the testicles.
Then there are things you cannot control. Sometimes your boys come under direct attack. Testicular cancer strikes about 1 in 100,000 men. The testicle has to be removed, but the cure rate is well over 90 percent and in most cases the other testicle can make enough testosterone to do the job. In more advanced cases, chemotherapy or radiation is needed. The cure rates are still really high, but the added treatment can rough up the other testicle to where it just can’t keep up. Really severe infections can permanently damage the testicles. Mumps can knock them both out at the same time. With infections, first there is a lot of swelling due to all the inflammation but, in the end, when the smoke clears, there is shriveling due to the damage done. Trauma, often during sports, takes an obvious toll. It’s key to wear a cup when the boys may get in the game. It may not be comfortable, but I have had to remove a busted nut more than once from guys in jujitsu tournaments who found a cup annoying.
Sometimes the problem is in your head—literally. The pituitary gland that sends the go signal to your testicles can develop a tumor that shuts that signal down. Sometimes it’s because the tumor is stealing the show, making too much of its own hormone, called prolactin, which upstages the LH and drives its level down. Another kind of tumor can arise that doesn’t make any prolactin but is so big it squishes the normal part of the pituitary so much that it chokes off any production of the signal.
A guy can be born with a condition that hurts his testicles and lowers his T. Some guys are born with an extra X chromosome, which carries instructions for female parts. These guys will still form normal penises, but the testicles will be small and will not produce sperm normally. In many cases the testosterone will be too low because the testicles cannot produce enough. In another genetic condition called Kallmann syndrome, the testicles can produce normal amounts of sperm but they don’t get the LH signal from the pituitary gland in the brain. This is because the guy is born without part of the pituitary gland and the nerves for the sense of smell.
A more common scenario is growing excessive veins around one or both of the testicles. These varicose veins are known as varicoceles. The veins feel squishy in the scrotum and are described in textbooks as feeling like a bag of worms. They usually don’t cause any trouble, but in a small percentage of guys their sluggish bloodflow heats up things too much, lightly roasting the nuts. The testicles are very finicky about temperature, and if the temperature is too warm by just a couple of degrees, the sperm can die off and occasionally testosterone production can take a hit. This is why our balls hang out but women’s ovaries are tucked away nicely inside. The ovaries don’t need this kind of special treatment. Also, this is why the sack will shrivel up when it’s cold but go slack (and sticky) when it’s warm—to try to keep that temperature constant.
Some boys are born with undescended testicles, where the balls don’t make it all the way down into the sack. This can happen to one or both sides and is usually fixed very early in life. Even so, there can be some permanent damage from the little guys staying in the warmer abdomen instead of down in the cooler scrotum, and some of these boys can end up with low testosterone and poor sperm production, especially if both of the testicles didn’t come down.
A more common cause of testicle injury is torsion, where a testicle gets twisted around and shuts off the very blood vessels that it hangs on. This causes a sudden and severe pain and has to be fixed within hours. It usually happens in younger boys and teens, so even if they end up losing the testicle, the other one often grows a little bigger to make up the difference.
Really severe physical stress, as in a major illness or military combat, can lower testosterone too.14 Men with kidney failure who are on dialysis will usually have low testosterone, as will many men with HIV. In these cases the stimulating signal from the pituitary is knocked down.15 Even a small percentage of longtime endurance athletes will show a similar pattern, though not as severe.16
Finally, inevitably, there is Father Time. It is said he waits for no man, but maybe he waits a little for the man who takes good care of himself. Nonetheless, he comes for your testosterone, and he almost always gets it. Starting in his thirties, a guy’s testosterone may start to slightly drop. By the mid forties, more guys start running low. Eventually, about half of men over 60 have low T, and by age 80 most men’s T is half of what it was when they were 30. To make matters worse, as the testosterone level is going down, the sex hormone binding globulin is going up. This means that even less of the testosterone that is still being made is free to do its job. Furthermore, the pituitary gland doesn’t kick in like it’s supposed to. Even if it did, the testosterone-producing cells in the testicles start to disappear.17 Most older men don’t walk around feeling truly low, but certainly the signs of erectile dysfunction, muscle weakness, brittle bones, irritability, depression, and overall frailty are unmistakable for many.
Figure 3 Fat lowers testosterone by turning it into estrogen, and estrogen lowers testosterone production.
Once you’ve checked the fuel gauge and found its reading low, there are several different ways to fill ’er up. It’s really important that you don’t go to a self-serve station and self-medicate with testosterone acquired without a prescription. You need full service with the supervision of a knowledgeable physician. Testosterone is a prescription drug for a reason, and in order for you to get the best results while avoiding serious side effects, the testosterone needs to be dosed properly and you need to be monitored regularly. The options include injections, implants, ointments, gels, liquids, patches, nasal sprays, and even a small globule that sticks to your gum, called Striant. Testosterone pills are not FDA approved in the United States because they can harm your liver. The same is true for any oral anabolic steroid. Watch out for herbal supplements that claim to boost testosterone naturally because they are often spiked with actual oral testosterone. In Europe there is a special formula of testosterone known as testosterone undecanoate that does not hurt the liver, but it is not as effective and reliable as the other types of testosterone treatments because it can be affected by what you eat and when you eat it.
When testosterone is put on through the skin, either as a patch or rubbed on, it wears off after about 24 hours so it has to be applied every day. It becomes a part of the daily grooming routine, like brushing your teeth or shaving. Unlike grooming, you can’t really skip it on a lazy weekend or a camping trip because these applications only last 24 hours.
The goal of these formulas is to get enough testosterone to bring you up to normal. For purposes of feeling well, good health, and longevity, the goal is to get into the range of 400 to 600 nanograms/deciliter. Going higher rarely changes how good you feel, and it’s not necessary from a long-term health standpoint. After you start on the T, the doctor will give it a couple of weeks or more to reach a steady state and then check your blood level again. If your T is too low or high, your doctor will advise you to change the dose.
Unfortunately, about 15 percent of men just cannot absorb testosterone very well through their skin. These tough-skinned guys will not get to the levels they need, even if they slather on extra formula. This is one reason why it’s so important for you to be monitored by a doctor and get your blood levels checked once you start down this path. For all you know, you may be one of the poor absorbers and you may be wasting your time and money.
With most formulas, enough testosterone is usually in your system by about 2 hours after application, so you can swim or shower at that point. But be careful, because even 24 hours later some of the testosterone you put on your skin can rub off on someone else’s skin. It’s recommended to take the added precaution of covering up the skin with a T-shirt. You will need to wash off the areas where you applied formula before any intimate contact. Try not to rub your exposed skin against children either. The T that rubs off can cause a woman to develop male characteristics or a child or infant to show signs of puberty—such as increasing pubic hair or inappropriate increase in size of the genitals—way too soon.
A tried-and-true method for getting testosterone into a guy is a needle. Granted, it hurts more than a gel or lotion, but it has its advantages too. For starters, it always works. There’s no one whose skin is too tough for a needle. There is also no risk of transferring testosterone to someone else.
Your doctor or the nurse will either give you the shots or teach you to give them to yourself. The injection is into a big muscle such as the thigh or the butt. It’s very manageable, but proper technique is important to help you avoid hitting a blood vessel or nerve. The dose the doctor chooses will be based on how often you get your shot. The testosterone slowly seeps out of the muscle into the bloodstream, and after a week to 10 days, half of it will be gone. Less frequent shots are more convenient for guys who go to the doctor’s office for their shots, but the trade-off can be feeling more of a roller coaster of highs and lows. My preference for my patients is a weekly injection, and I teach them to do it themselves. Twice a week with an even lower dose is good for a few guys who really feel the difference between the beginning of the week and the end of the week, but this isn’t necessary in most cases. A longer-lasting injection known as AVEED must be given in the doctor’s office, but it lasts for 10 weeks.
If getting a shot every 10 weeks is still too much hassle, then consider the implantable pellets. Several of these pellets are tunneled into the buttocks through a small nick in the skin after the doctor numbs you up with a shot of lidocaine. The pellets dissolve more slowly than the oil-based T injections. Normal T levels can be maintained for 3 months and, in some cases, even up to 6 months. Once the pellets are in, a butterfly bandage is placed and you have a sore butt and maybe a bruise for a few days. Occasionally there can be bleeding that requires more attention or an infection, but this is pretty rare.
Not everyone can handle needles, and when the skin-based formulas don’t work, there are still other options such as Striant, a small globule that you put on your gum twice a day like a little pinch of chewing tobacco. It’s like a testosterone patch for your gum. Natesto is a gel you squirt up your nose three times a day.18
When you use testosterone, it powers down your testicles. The testosterone that you put into yourself circulates to the pituitary gland, which senses that you have “enough” testosterone and so stops trying to get your testicles to make more. Without the LH signal from the pituitary, the testicles stop making any testosterone at all. The pituitary also stops sending the testicles the follicle-stimulating hormone (FSH) signal to make sperm, and that is why guys who take testosterone get shrinkage of their testicles. This shutdown occurs in only a few months. The only way you can protect your testicles while you are on testosterone is to be prescribed low-dose HCG (human chorionic gonadotropin) injections every other day.19 Even this is not foolproof, but the only time it’s really important is for guys who need the sperm because they’re trying to have a child.
A more common solution for guys who have low T but are trying to have a child is for a doctor to prescribe a pill called clomiphene citrate (aka Clomid), which tricks the good old pituitary gland into making even more LH and FSH signals to make the testicles produce more of their own testosterone and keep churning out sperm. Instead of shutting down the testicles, it revs them up. Many people think of Clomid as a female fertility drug, but in this case what’s good for the goose is also good for the gander. Side effects can be mild strain on the liver or feeling less sexual in spite of higher testosterone. Also, estrogens can get boosted along with testosterone, so close monitoring is important.
Another pill that can work, particularly in obese men, is anastrozole, brand name Arimidex. It blocks the fat cells from turning testosterone into estrogens. This raises the testosterone without turning off the pituitary signals to the testicles. It can also be used to lower estrogen levels if they get too high while on Clomid. Arimidex is available by prescription and its use needs to be monitored because if it lowers the estrogens too much, the bones can get weakened.
Figure 4 Effect of prescription hormones on testosterone production
Figure 5 Blocking the conversion of testosterone to estrogen with Arimidex
The benefits of testosterone are the same regardless of the mode of treatment. It restores good health and prevents other problems down the line. Restoring testosterone to normal lowers the risk of getting diabetes or lessens its severity. It lowers the risk of becoming obese while helping build muscle. It prevents bones from getting brittle and helps build back weak bones. It reverses depression and anxiety when they are due to low T. The vast majority of studies also indicate a benefit to cardiac health, lowering the rate of heart attacks, strokes, and death.20, 21
T replacement actually increases the life span of men, compared to those who go without treatment.22
Okay, life and death, blah blah blah, but what about sex? Testosterone restores sexual desire in men who are low, but desire is a complex emotion, and even when T levels are normal other issues may get in the way. Even so, if T is low, there isn’t a chance for normal desire no matter what the other issues may be. Testosterone improves erections, but usually not as a “standalone” drug. In older guys, other health issues may cause erectile dysfunction. In such cases pills or injections will often be required to pump up the bloodflow. But without restoring testosterone, those medications will often not work well enough, so T replacement can make all the difference. It can sometimes take many months for the testosterone to revive the penis tissues fully or at least enough that they respond better to the penis pills or injections. Restoring testosterone can restore pleasure and sensation during sex as well, and sometimes increase the ability to reach a climax or ejaculate.
The good news is testosterone can really help a guy when he is down. The bad news is that, as with any medication, there are side effects and risks. One side effect is swelling in the legs. This is uncommon, but water gain can give you a few more pounds on the scales when you first get started. Also, as the levels of T in your system get higher, you may develop acne and you may get some nipple tenderness. If the levels are getting too high, you may even get some breast tissue growth as the excess T is converted to estrogens in your fat cells.
Testosterone can overstimulate your red blood cell production, leading to thicker, more sludgy blood, so your blood counts should be monitored and if they get too high the doctor will likely lower the T dose or stop it altogether. You may even be instructed to have some blood removed. Testosterone can lower your voice because it can increase the size of your larynx (voice box), but this can also aggravate sleep apnea if you have it.
Prostate cancer is common, but no more so in men on T than in men off T. Nonetheless, your prostate should be monitored at least once a year with a rectal exam and a PSA blood test. The official label from the FDA states that T replacement should not be used in anyone with a risk or history of prostate cancer. In many expert urology practices, as long as a guy has had a prostate cancer treated successfully, he can get back on T replacement. Some doctors will even treat men with prostate cancer that hasn’t been removed but watch them very closely. A less common but more dangerous risk is breast cancer. Although it is rare, it can be exacerbated by increased amounts of estrogens that may form in the fat as T levels rise. No one with a history of male breast cancer should use T.
For the vast majority of men who need testosterone replacement, the benefits clearly outweigh the risks. As with any legitimate medication, treatment should be under the supervision of a knowledgeable doctor, with regular monitoring of blood levels and regular physical examinations. If you suspect your testosterone is low, check with your doctor and make sure you are running on all cylinders.