Do You Need to Fast for a Testosterone Test?

Some studies show that about 5 million men in America, mainly older men, have low testosterone levels. This problem is known as hypogonadism. It can cause serious effects that impact your quality of life. To find out if someone has hypogonadism or testosterone deficiency, several tests are done.

Patients usually take one or more testosterone tests to check their levels. Recent studies show that your testosterone levels can change a lot if you do the tests on an empty stomach. In simple words, eating before a testosterone test can impact the results. This article looks at the connection between testosterone levels and fasting. Keep reading to find out more about testosterone testing.

How to Diagnose Low Testosterone ?

Testosterone levels peak in the morning for healthy men. After 11 AM, these levels start to decline and keep dropping through the day. Typically, testosterone tests happen in the morning, as this is when hormone levels are highest.

If you exhibit common signs of low testosterone, such as a low sex drive or no interest in sex, you may need to undergo testing. Other signs include trouble focusing, feeling tired, and signs of depression. A few tests are needed to see if you have low testosterone.

Your doctor might check your FSH and LH levels. These hormones come from the pituitary gland. They help begin the process of making testosterone. This process increases muscle mass and produces sperm in the testicles.

A healthy man should have testosterone levels between 350 ng/dl and 1,250 ng/dl. This depends on the lab tests. If the levels drop below 350 ng/dl and there are symptoms of low testosterone, this might mean he has hypogonadism. Testosterone levels can vary a lot. They can be affected by the time of day, what you eat, how old you are, how fit you feel, and several other things.

Testosterone tests are typically done in the morning. This is when testosterone levels are at their peak, as noted by the Endocrine Society. Doctors and labs do not require patients to fast before the test. Still, some studies suggest that fasting before a testosterone test can significantly affect the results.

Purpose of the test

The testosterone test checks how much testosterone is in your body. This hormone is key for several body functions. A health care professional usually asks for this blood test when someone shows signs of low testosterone. These signs can be feeling tired, having a low sex drive, or mood swings.

The testosterone levels test can help find issues like hypogonadism. If not treated, hypogonadism can lead to several health issues. By looking at the testosterone levels, which might be too high or too low, doctors can tell if more tests or treatment are needed. A common treatment is testosterone replacement therapy. This helps get your hormone levels back to normal.

What Is the Link Between Fasting and Testosterone Levels?

Fasting usually means not eating for a certain period, often between 8 and 12 hours. During this time, you should also stay away from drinks that make your body work harder, such as alcohol and milk.

Many blood tests require you to fast before taking the sample. This is called a fasting blood test. A common example is the standard glucose test. If you eat before this test, your results might indicate that you have diabetes, even if you do not.

That is because your body did not have enough time to change the glucose in your blood. This will show up in a test. Scientists believe that fasting is also important for checking your testosterone levels.

Eating before your test could drop your testosterone levels temporarily. If your normal T level is around 400-500 ng/dL, this might make it look like you have low testosterone. Because of this, it’s crucial to retest people who were initially told they had low testosterone.

Let's look at some studies. We will take a closer look at the connection between fasting and testosterone tests. You will see how having glucose or a complete meal can change total and bioavailable testosterone levels several hours after eating.

Study 1 - Testosterone Decreased Significantly After an Oral Glucose Load

This study focused on 74 men. They were about 50 years old, with some being a few years younger or older. The research happened in 2012. The men took a standard test where they drank 75 grams of glucose. This was done to see how well their bodies could handle it.

A glucose tolerance test measures how well your body processes glucose after you drink a sweet beverage in a lab. If your body handles it quickly, your glucose tolerance is good. If your blood glucose takes a long time to process, it could suggest you have diabetes or other health issues.

Almost 60% of the men in the study had normal blood sugar levels. Over 10% of them were recently identified as having diabetes. About 30% of the patients had problems with their blood sugar levels. Blood samples were collected from each person at the beginning of the study and then again after 30, 60, 90, and 120 minutes.

Other hormones and substances were tested too. This includes insulin, leptin, sex hormone binding globulin (SHBG), and total testosterone. When the study began, none of the people involved had low testosterone levels.

The results were surprising. The study found that testosterone levels dropped by around 25% after people consumed glucose. This is a significant change, especially since most participants had normal glucose tolerance.

If someone has a normal testosterone level of 500 ng/dl, a 25% drop will bring it down to around 375 ng/dl. This number is very close to the lowest normal testosterone levels.

The drop in testosterone was observed again after 120 minutes. Blood samples were taken one last time then. At the study's end, 10 people had testosterone levels that were below the normal range. This suggests they could be diagnosed with hypogonadism.

This study shows why it's important to take a testosterone test while fasting. A small amount of glucose can reduce total testosterone levels. This can wrongly indicate that someone has hypogonadism.

Study 2 - Eating a Meal Can Significantly Decrease Testosterone Levels

Let’s examine a study about how testosterone levels are connected to feeding and fasting. This study shows that eating a meal with 550 calories from protein, fat, and carbohydrates can change testosterone levels.

Eleven healthy men joined this study. They did not smoke, were not treated for health issues, and had a normal body mass index (BMI). Their average age was 43 years. These men also had no major health problems in their past. This highlights the importance of lifestyle changes for overall health.

In the first part of the study, participants had a meal that had 550 calories. This meal had buttermilk, cheese, ham, orange juice, and more foods. Blood samples were collected at several times. The study also looked at different hormones. These hormones included LH, SHBG, and glucose.

The people in the study took around 15 minutes to eat their meals. The food served was different on purpose. The study creators aimed to create a meal that many men typically enjoy.

People had to not eat for 12 hours before getting this meal.
They were also asked to avoid sex and heavy workouts.
This was important because these activities could affect their testosterone levels.

The researchers repeated the same steps a few weeks later with the same group. This time, they did not eat for 12 hours. They took blood samples while the group was still fasting. Everything else in the study was the same.

When we looked at these two experiments, the results were impressive. Both groups had the same starting fasting testosterone levels. Other hormones, like LH and SHBG, stayed the same too.

The testosterone levels went down in the fed group just 15 minutes after they ate. This drop kept going even after 30 minutes. Other hormones and factors did not change. The only ones that dropped a lot were the total and bioavailable testosterone levels.

After reviewing the results, the experts noticed that testosterone levels went down by about 30%. This happened to every participant in the study. The study also showed that measuring testosterone levels while fasting is not the same as checking them after eating.

What happens during a testosterone levels test?

During a testosterone levels test, a health care professional will take a small amount of blood from a vein in your arm. This process is quick and usually takes less than five minutes. Before the test, talk to your healthcare provider about any steps you might need to take, like fasting. The results of the blood test will show if your testosterone levels are in the normal range. This information can help your doctor decide what the next steps should be for your health management.

Before the test

Before taking a testosterone test, it’s smart to talk with your health care provider. You may need to prepare for the test. A physical exam can check your overall health. It’s also important to talk about any medical conditions you may have. These can change your testosterone levels. Being healthy before the test will help you get better test results.

How do I prepare for a testosterone test?

Preparing for a testosterone test means taking a few important steps to ensure accurate results. Here are some rules to follow:

Schedule the test for the morning when testosterone levels are typically at their highest.
Ask your healthcare provider if you need to fast before the test.
Avoid intense workouts or sex for at least 24 hours before the test. These can temporarily affect testosterone levels.
Inform your provider about any medications you are taking, as some can change your test results.

Checking your testosterone levels the right way is important. Following these steps can help you. This will lead to a good diagnosis and treatment for low testosterone.

Key Takeaway for Future Testosterone Testing Protocols

The studies in sexual medicine show that your diet can affect testosterone levels. Currently, you do not need to fast before testing. These findings could potentially transform the future of testosterone testing.

There were not many big differences in LH, SHBG, and other hormones among the people in the study. This means that the hypothalamic-pituitary-testicular (HPT) axis was not greatly affected by food or glucose intake. However, testosterone production changed. It looks like insulin, which the pancreas makes when we eat to control glucose, could quickly lower testosterone production in the testes.

If you think you have low testosterone, look at these tests. You can order them online at a good price. This way, you can see how your hormones are working.

Receiving test results

After your testosterone levels test, you will receive your test results in a few days. Your health care provider will contact you to discuss the results. If your results show abnormal testosterone levels, you might need more checks. This can help find the cause and the best treatment options.

Interpreting test results

Interpreting testosterone test results means checking the reference ranges provided by the lab. Normal testosterone levels can vary greatly based on your age and sex at birth. Your healthcare provider will help you understand if your testosterone levels are normal, low, or high. They will explain what this means for your health.

What do the results of a testosterone test mean?

The results of a testosterone test show your total testosterone level. This info can help check your hormonal health. A low total testosterone level might mean you have hypogonadism or other health issues. High testosterone levels may suggest problems like tumors or effects from hormone therapy. It is important to understand these results. This way, you can decide how to manage your testosterone levels well.