Labs for Libido: How to Test for Low Testosterone

On: January 10, 2019
Hypothyroidism, low testosterone, sexual health

If you’re worried about testosterone, you’re not alone. About 25% of men over 30 have the same problem.

Thankfully, with the right testing and treatment, you can get a handle on this problem, whether you’re 35 or 75.

First, your doctor will confirm your testosterone levels through a blood test. Don’t worry, even if you have low testosterone (T) there is a lot you can do to reverse it.

This article will walk you through how to test for low testosterone. We’ll also share some brief information on how testosterone therapy works.

First, Let’s Talk About Symptoms.

If you notice any of these symptoms ask your doctor about testing for low T. The early signs of low T include:

  • Low libido
  • Erectile dysfunction
  • Low sperm count
  • Losing body hair
  • Hot flashes

If you still have questions about low testosterone and what causes it, this article should answer a lot of them.

How to Test for Low Testosterone

Next, let’s discuss the two kinds of testosterone tests. Your doctor may only use one of these tests depending on your symptoms. The two tests are:

Free Testosterone Test – Testosterone attaches itself to albumin and sex hormone binding globulin (SHBG). A free testosterone test checks only for testosterone not attached to proteins.

Total Testosterone Test – Checks for both attached and free testosterone levels.

If it’s possible, make your test appointment for the morning. This is when T levels are at their highest. Tell your doctor beforehand if you are taking any supplements or medication.

What’s Next After Testing?

Because low testosterone levels are often a sign of other health problems, your doctor will evaluate what to test for next. These follow-up tests often include:

  • A biopsy to check for cancer.
  • Test estrogen levels. Unbalanced estrogen levels can lead to many degenerative diseases in men. The main concern is atherosclerosis, a condition where fat and cholesterol harden the walls of your arteries.
  • Follicle-stimulating hormone (FSH) or luteinizing hormone (LH) – Low FSH in males is correlated with lower testosterone.
  • Prolactin – A hormone that resides in men in small amounts. Heightened levels of prolactin can be a sign of some serious health issues, like kidney disease or liver failure.
  • Sperm Analysis – Checks for volume, speed, and size of your sperm

So now that you know what might be coming after a testosterone test. Let’s talk about some of the limitations of these tests and why you may want a second opinion

No Standard Testosterone Range

Now that we know how to test for low testosterone, let’s talk about the results. Low testosterone diagnosis occurs when levels drop below 300 nanograms per deciliter (ng/dL). But there has never been a consensus about the exact number. One doctor might wait until your levels drop closer to 200 ng/dL. Another may start you on a testosterone replacement regimen as soon as you get close to 300 ng/dL.

Accuracy is another issue with testosterone testing. You can get different results from the same testosterone labs given at another time. It’s estimated that close to a third (30%) of men who test for low T levels score in the normal range when they take the test again.

The reason for these discrepancies goes back to the topic of free and attached testosterone. Free testosterone only makes up about 1-2% of your total T levels. But it is ready for your body to use. Only about half of your attached testosterone, the kind attached to albumin, is ready for use like free testosterone. Any of the hormone attached to SHBG isn’t usable.

Because testosterone binds so tightly to SHBG, it isn’t readily available for the body to use. So its presence might elevate the results of your testosterone test, but it doesn’t have an effect on your body.

Causes of Low Testosterone

So what causes low testosterone? Age is the biggest factor, but it’s not the only reason men lose testosterone. Causes other than age include:

  • Injury or infection
  • Chemotherapy or radiation treatment for cancer
  • Medications, especially hormones used to treat prostate cancer and corticosteroid drugs
  • Chronic illness
  • Stress
  • Alcoholism
  • Obesity

It’s important to take any of these causes into consideration before beginning testosterone therapy. If you have an acute case of low testosterone, taking supplemental testosterone can mess with your regular hormone levels.

Why FSH and LH Levels Matter

Primary hypogonadism diagnosis occurs when tests show low FSH and LH in males. Hypogonadism is when consistent blood tests show low testosterone. Primary hypogonadism is mostly seen in individuals with Klinefelter Syndrome. This is a condition where males have an extra X chromosome.

Secondary hypogonadism is when the hypothalamus doesn’t produce gonadotropin-releasing hormone (GnRH). FSH and LH levels may be below normal or appear normal, but testosterone will be lower than average. This is the kind of low testosterone we see in ageing men.

Are Other Health Conditions Affecting Your Low Testosterone?

Men with type 2 diabetes are twice as likely to have low testosterone levels. Insulin resistance is common in men with low T even if they are not obese. About one in four men who see their testosterone drop to low levels also see a rise in their insulin resistance.

But low T may be a side effect of type 2 diabetes as well. In a study looking at hormone levels in diabetic men, over one-third had low levels of free testosterone. So type 2 diabetes seems to have a direct effect on the testosterone that is available for your body to use.

That doesn’t mean losing weight won’t raise testosterone. Studies show that as body mass index (BMI) rises above healthy levels, testosterone declines. The good news is overweight and obese men suffering from low hormone levels may see a reversal in their testosterone by losing weight.

Another study looked at the effects testosterone therapy had on men with type 2 diabetes and low hormone levels. Some studies have shown an increase in heart problems in men prescribed testosterone. But one study found that testosterone lowered insulin resistance. This coupled with weight loss significantly lowered participants’ risk of heart disease.


The thyroid plays a big part in testosterone production. Your thyroid regulates the number of hormones flowing throughout your body. When your thyroid is underactive, your body is not producing enough vital hormones.

Because low T is often a sign of hypothyroidism, it’s important to spot the warning signs early on. These symptoms include:

  • Sensitive to cold weather
  • Weight gain and a hard time losing weight
  • Slower than average heart rate
  • Fatigue
  • Dry hair and skin
  • Depression
  • Enlarged thyroid gland

What Happens After All the Testing?

If you do have low T, don’t panic. There are a lot of treatment options. No treatment will be an overnight fix, but you can start to ease some of your symptoms.

Testosterone replacement therapy comes in a variety of forms. The most common being a topical gel. The benefits of the gel include:

  • Easy to apply. Injections require an appointment with a health care professional. The gel is easy to apply on a daily basis with no help.
  • Increased libido. Men reported increased sex drive and performance. It is important to note that this was the most reported benefit of testosterone therapy.
  • Higher self-confidence. That same study measured increases in the distance during a six-minute walk before and after receiving treatment. There were no significant differences, but men on the gel felt stronger about their walking abilities.

So What Are the Risks?

This study took place over 12 months, so we can’t make long-term assumptions. The two major concerns over testosterone gel use over time are prostate and heart problems.

Research on testosterone replacement therapy is still in its infancy. We can’t say for certain what will happen from taking testosterone long term.

UCLA conducted a study with 55,000 men. Participants over 65 saw a two-fold increase in heart attacks within the first 90 days of taking testosterone. Men under 65 with a history of heart disease saw their rate of heart attack increase by two to three-fold in the first 90 days after taking testosterone.

Because the side effects can be life-threatening, it’s important to go in for multiple tests before starting hormone therapy. You should take at least two tests before beginning treatment.

“How Do I Take Testosterone?”

Testosterone therapy comes in multiple forms. Your doctor may prescribe any of the following methods:

  • Patch. A small patch applied every 24 hours gives a consistent dose of the hormone
  • Gel. A topical gel applied to clothed parts of the body
  • Tablet. Tablets attach to the mouth twice a day and release testosterone into the bloodstream
  • Pellets. A more invasive type of therapy. Pellets go under the skin around the hips and release testosterone over a period of 3 to 4 months.
  • Injections. Administered every two weeks, injections often cause sharp changes to your mood. Hormone levels peak a few days after the injection and then drop off until the next treatment.

Testosterone Therapy and Prostate Cancer

It is standard for doctors to avoid prescribing testosterone to men with prostate cancer. But new research is showing that this may not be necessary.

A study that tracked the progression of prostate cancer in men taking testosterone found no correlation between the two. The difference could be in the form of testosterone taken.

Testosterone therapy replaces free testosterone without raising attached testosterone. Testosterone treatment may not be out of the question if you have prostate cancer.

Testosterone and Libido

Sex drive and erectile dysfunction are two of the main reasons men seek out testosterone treatment. 28% of men with low T reported a lower than normal sex drive. But erectile dysfunction is rarely caused by low testosterone.

Atherosclerosis, the hardening of arteries, is the most common cause of erectile dysfunction. The small arteries in the penis aren’t getting proper blood flow.

So while testosterone is a component of libido, erectile dysfunction is often a sign of other health issues.

Erectile Dysfunction

It’s important to cover possible causes of erectile dysfunction (ED) when discussing testosterone levels. ED is often the reason men first seek out testosterone therapy. While lowered testosterone can be a side effect of ED, as we’ve said before, it is a forewarning of cardiovascular disease.

What’s interesting to note is that both heart disease and ED list low T as a side effect. Treating these other conditions can have a positive effect on testosterone levels.

How to Raise Testosterone Levels Without Medication

Men wishing to avoid the serious risks that come with hormone therapy may be looking for natural ways to boost their testosterone. Here are some drug-free ways to boost testosterone production.

  • Weightlifting. Lifting weights increase testosterone in men of all ages. In obese men, increased physical activity raised T levels more than a weight loss diet. A study found a relative increase in testosterone levels in comparison to the number of steps per day.
  • Reduce stress. The dangers caused by the stress hormone cortisol are widely known. Long-term stress can affect everything from cognitive function to heart health. It’s no wonder cortisol has a diminishing effect on testosterone.
  • Take Vitamin D. A yearlong study found that taking 3,000 IU of Vitamin D3 every day raised testosterone levels by 25%.
  • Zinc and vitamin B have an even greater effect on T levels. One study showed these supplements to improve sperm quality by 74%. While the study did not specifically look at testosterone, sperm development is directly related to testosterone production.
  • Get quality sleep. Sleeping only 5 hours a night has shown decreases in testosterone of up to 15%. Men getting four or fewer hours of sleep each night were borderline deficient when it came to testosterone production.
  • Try ashwagandha. Ashwagandha is an herb that can reduce cortisol and boost testosterone levels up to 18.7%.

“Is Testosterone Therapy Right for Me?”

Research on the long-term effects of testosterone therapy is still inconclusive. The biggest takeaway is to only start a testosterone regimen if repeated testing proves you have low T levels.

The biggest benefit of testosterone therapy is a stronger sex drive. Energy levels stayed relatively the same regardless of testosterone use. But men did self-report feeling more energetic.

Talk to your doctor about how to test for low testosterone.  Again, 25% of men over 30 struggle with low testosterone. Thankfully, there’s a lot you can do about it. And you can start right now. Click here to talk to a doctor about getting tested and/or starting testosterone therapy today.

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