Testosterone tends to fluctuate during the day and during the season. There are a couple of factors that influence these fluctuations. With these things in mind, it’s important to do things right before you measure testosterone levels or else you might even end up (artificially) with testosterone deficiency.
In this article, I’m going to show you how much it fluctuates and what likely causes it. Let’s dive in.

Hans here! I increased my testosterone to 1254ng/dl and have been maintaining high T naturally. I’ve turned myself into an Alpha Energy Male.
An Alpha Energy Male with high energy, fast recovery, high sex drive, and confidence.
This is why I research obsessively, experiment and write, and have been doing so for the past decade.
Hope you enjoy and join me on this journey.
Why do we want to be an alpha energy male?
Being an alpha energy male is synonymous with possessing both high testosterone levels and abundant energy. Consequently, the question arises: what exactly is the significance of having elevated testosterone and energy levels?
Because high T and energy make us feel incredible and powerups our motivation, drive, confidence, and sexual function.
A life without high T and energy isn’t a life worth living.

Understanding daily testosterone fluctuations
Total testosterone levels in men can vary significantly throughout the day, and even over days, weeks, and months. The highest levels of testosterone are typically found in the morning upon waking up, and they gradually decline throughout the day. Research has shown that normal testosterone levels can fluctuate by as much as 30% to 40% within a single day, highlighting the dynamic nature of this hormone in the male body.
How much does daily total and free testosterone fluctuate
Study 1 – daily testosterone fluctuations
Young men had a greater daily variation compared to elderly men (1.42 +/- 0.38 vs 0.38 +/- 0.07 nM/l) (R). As you can see in the graph below (one on the right), free testosterone fluctuated more than total testosterone in young men (top line) with almost no variation in elderly men (bottom line).

Study 2 – daily testosterone fluctuations
According to this study, total, free and bioavailable testosterone declined by 24%, 34%, and 15-45% after 9am. This shows that free and bioavailable testosterone potentially declines more than total testosterone over the day. This is interesting since most people start to feel better later in the day compared to the morning (R).
Study 3 – daily testosterone fluctuations
In men 30–40 years old, testosterone levels were 20–25% lower at 4pm than at 8am. The difference declined with age, with a 10% difference at 70 (R). As you can see in the graph below, the higher your testosterone, the bigger the decline over the day. Guys with T over 700ng/dl experienced a 20% decline whereas guys with 200-300ng/dl had an 11% decrease.

How much do testosterone levels fluctuate across seasons?
Norway – seasonal testosterone fluctuation
Norway is interesting because the temperature varies from -4C in the winter to 8C in the summer. Also, in the winter the days are about 3 hours long and in the summer, the sun doesn’t set between May and July.
Interestingly, testosterone was at its lowest in the summer. Also, there was a 31% difference in free testosterone between winter and summer (R).

Finland – seasonal testosterone fluctuations
This study in Finland found no significant seasonal variation in testosterone (roughly 12nmol/L (346ng/dl) average testosterone) and Finland has nearly the same day lengths as Norway (R). So it must be a cultural thing that lowers testosterone in the summer in Norway (maybe lots of drinking? If you’re from Norway, let me know in the comments).
Denmark – seasonal testosterone fluctuation
In Denmark, testosterone correlated with temperature (R). Thus testosterone is higher in the summer and about 15-20% lower in the winter.

Isreal – seasonal testosterone fluctuation
In Israel, winter starts at about November and lasts until the end of March and the temperature in most parts of the country is moderately cold and rainy. In April, the temperature rises gradually, and from June until about the mid of September, the weather becomes hot without rain.
Total and bioavailable testosterone was higher during the summer-autumn season and lowest in the winter (R).

The peak of male hormone levels in summer correlates with longer daylight duration and higher temperature (R). Also, generally, there is a significant increase in physical activity during the summer months, which also contributes to higher testosterone.
Turkey – seasonal testosterone fluctuation
Testosterone changes from winter to summer were quite significant.

Also, these men had more sexual thoughts (28.1 vs 17.4) and ejaculated more (7.16 vs 2.31) in the summer than in the winter (R). This is well in line with the research showing that sexual function, libido and sexual attraction is higher in the summer than the winter.

In Turkey, the winters are on average -15.9°C and the summers 25.4°C.
Southwest US – seasonal testosterone fluctuation
Total and free testosterone and DHEA-S didn’t vary with the season, but the testosterone-to-estrogen ratio peaked in the spring and was at its lowest in the fall. This is in line with bodyweight changes. People likely gain more weight in the winter and produce more estrogen, which is what alters the testosterone-to-estrogen ratio (R).
Buenos Aires – seasonal testosterone fluctuation
Despite most other studies finding high testosterone in the summer, this study found that these men had lower T in the summer. They also had high estradiol and a low testosterone-to-estrogen ratio. I have no way to explain this, so if you’re from Argentina, drop a comment as to why this might be (too humid, too many pesticides, excess partying, etc.?).
Total testosterone and free testosterone decreased from 501.9±157.7 to 405.0±128.0 ng/dL and 11.8±4.1 to 10.2±3.7 ng/dL from the winter to summer. The testosterone to estradiol ratio decreased from 30.7±19.7 to 17.3±3.6 in the winter to summer (R).

Province of Modena, Italy – seasonal testosterone fluctuation
In Italy, testosterone increased in summer and was at its highest when temperatures were highest and days were the longest.

Factors Affecting Total Testosterone Fluctuations
Several factors can influence testosterone fluctuations in men. Some of the key factors include:

#1 Age
Testosterone levels tend to decline naturally as men age. After the age of 57, seasonal testosterone fluctuations tend to disappear.
➡️Average testosterone levels with age. Does testosterone really decline?

#2 Lifestyle Factors
Lifestyle choices, such as diet, exercise, and sleep patterns, can significantly impact testosterone levels. A sedentary lifestyle, poor diet, and lack of exercise have been associated with lower testosterone levels.
Physical activity usually spikes during the summer and exercise is known to positively influence testosterone.
However, sleep might also suffer more during the summer in places where it’s really hot and humid.
Lastly, due to technology (air conditioners, heaters, etc.), we can control the environment for the most part. This might also be why testosterone doesn’t fluctuate as much in various studies compared to others.

#3 Stress
Chronic stress can disturb the hormonal balance in the body, leading to fluctuations in testosterone levels. When stress levels are high, the body produces more cortisol, a stress hormone, which can suppress testosterone production.
Winter can be seen as a stressor and a lot of people suffer from seasonal affective disorder (SAD; indeed) in the winter.
➡️The complete guide on how to lower cortisol

#4 Weight and Body Composition
Weight gain, particularly excess fat around the waistline, has been linked to lower testosterone levels. Adipose tissue, or fat, can convert testosterone into estrogen, a female sex hormone, leading to an imbalance in hormone levels. Achieving and maintaining a healthy weight and body composition is important for testosterone regulation.
In the winter, people tend to move less and eat more, which can lead to weight gain. On the other hand, younger people tend to party more in the summer and gain more weight during that time.

#5 Illness and Medications:
In the winter people are more likely to be on meds due to depression or anxiety or even sleep issues. Many drugs, such as anti-depressants, lower testosterone.

#6 Testicular temperature
Warm testes (>35C) don’t produce as much testosterone as cooler testes (35C). Obesity, warm baths and prolonged sitting are known causes of warm testes, which can lower testosterone.

#7 UV light
UV light has been shown to promote the release of LH (R). Specifically, ultraviolet B (UVB) exposure enhances the levels of sex-steroid hormones and sexual behavior, which are mediated by the skin through p53 (R). UVB exposure also enhances the sexual responsiveness and attractiveness of females and male-female interactions. “In humans, solar exposure enhances romantic passion in both genders and aggressiveness in men, as seen in analysis of individual questionaries, and positively correlates with testosterone level.“
➡️Complete guide on how to increase LH
The Effects of Testosterone Fluctuations
Testosterone fluctuations can have several effects on men’s physical and mental well-being. Some of the potential effects include:
Sexual Function
Testosterone is crucial for maintaining sexual health and function in men. Fluctuations in testosterone levels can impact libido, erectile function, and overall sexual performance.
As you can see from the Turkey study, in the summer, men had much higher libido as well as erections.
Mood and Emotional Well-being
Testosterone levels can influence mood and emotional well-being. Low testosterone levels have been associated with symptoms of depression, irritability, fatigue, and decreased motivation. It’s common to have low mood in the winter. A bright warm day in the middle of winter is always great for mood and overall morale.
Muscle Mass and Strength
Optimal testosterone levels are essential for the development and maintenance of muscle mass and strength. Fluctuations in testosterone can impact muscle growth, recovery, and overall physical performance.
Managing Testosterone Fluctuations
Men interested in maintaining optimal testosterone levels can take certain steps to support hormonal balance and well-being. Here are some strategies to consider:
Healthy Lifestyle Choices
Eating a balanced diet, engaging in regular exercise, and getting sufficient sleep can help support testosterone levels. Focus on consuming nutrient-dense foods, such as dairy, organ meat, muscle meat, shellfish, eggs, tubers, etc. Incorporate strength training and cardiovascular exercises into your routine. Aim for 7-8 hours of quality sleep each night.
Stress Management
Implementing stress management techniques, such as exercise, mindfulness meditation, and engaging in activities you enjoy, can help reduce cortisol levels and support healthy testosterone levels.
Weight Management
Maintaining a healthy weight and body composition is important for hormone regulation. Focus on a balanced, calorie-controlled diet and engage in regular physical activity to manage weight effectively.
➡️You can expect a 100ng/dl increase in testosterone for each 10% of bodyweight loss.
Regular Physical Activity
Regular exercise, such as strength training and cardiovascular activities, can stimulate testosterone production and support overall well-being.

FAQ and related questions
Does staying up all night cause low testosterone?
Yes and no. Some studies show that even 1 night of sleep restriction can lower testosterone by 10-15% whereas another study found that sleeping only 4 hours for 5 nights in a row didn’t lower testosterone.
Sleeping poorly for one night is not as bad as doing it chronically. Chronic sleep deprivation and disturbances in sleep patterns have been associated with reduced testosterone production. Sleep is known to play a critical role in regulating hormone production and release, including testosterone. Disrupting this delicate balance by consistently depriving yourself of sleep can potentially result in lower testosterone levels over time.
To maintain healthy testosterone levels, it is generally advised to prioritize regular and sufficient sleep. Aim for 7-9 hours of quality sleep per night, establish a consistent sleep routine, create a sleep-friendly environment, and prioritize good sleep hygiene practices.
Does ejaculating once a day lower testosterone?
Ejaculation hasn’t been shown to lower testosterone on test results and semen retention has not been shown to increase testosterone.
In fact, some studies have suggested that sexual activity may actually increase testosterone levels temporarily. This could be due to the release of endorphins and other feel-good hormones during sexual arousal and orgasm. However, this increase is typically short-lived and returns to baseline levels relatively quickly.
➡️Semen retention on testosterone: a secret warrior hack or a hoax
What time of day is testosterone the lowest?
Testosterone is lowest in the evening and then increases again after a good night’s rest. This daily fluctuation is almost flat for elderly men.
What time of day is testosterone the highest?
Around 6-9am in the morning. Sleep deprivation has been shown to blunt this spike.
What are the average testosterone hormone levels by age?
The average testosterone over age is 450-550ng/dl. It’s a common myth that testosterone decreases by 1% per year after the age of 35.
Summary – Do testosterone levels fluctuate
Testosterone levels in men naturally fluctuate throughout the day and can be influenced by various factors such as age, lifestyle choices, stress, weight, and illness. Understanding the reasons behind these fluctuations is essential for men interested in maintaining optimal testosterone levels and overall well-being. By adopting healthy lifestyle choices, managing stress, maintaining a healthy weight, and seeking professional guidance when needed, men can support their testosterone levels and enjoy the benefits of balanced hormones.
➡️The complete guide on how to maximize testosterone
➡️How to increase free testosterone
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>1000ng/dl Testosterone: My Step-by-Step Guide on How I Do It Naturally!
Thanks. Would like to understand also, the effect of eating per se on free T. A huge meal increases insulin and this affect free T negatively. Maybe eat smaller meals more often?
Food enhances the tissue uptake of hormones, so the drop isn’t bad. The key when it comes to digestion is not to overeat and also to avoid foods that cause indigestion and inflammation.