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5 Warning Signs of Low Testosterone: What Every Man Needs to Know
If you’re constantly feeling tired and struggling with weight gain, you might be wondering if low testosterone is the culprit.
And you could be right.
I call testosterone the hero hormone for guys because it influences energy levels, mood, body composition, and overall vitality. It's the first place you should look if you don't feel like yourself anymore.
Yet, many men suffering from low testosterone go undiagnosed because they rely solely on a lab result rather than paying attention to their symptoms.
In this article, we’ll break down five of the most common warning signs of low testosterone—beyond just looking at a number on a lab test. Let’s dive in.
Why Symptoms Matter More Than Just a Number
Before you rush into testosterone replacement therapy (TRT) or grab a T booster supplement, it’s essential to determine whether testosterone is truly the issue. The key? Look at both symptoms AND levels.
Most guys assume that if their bloodwork shows “normal” testosterone levels, they’re in the clear. But that’s not always the case.
If you’re experiencing the following warning signs, your testosterone may still be too low for YOU—even if your doctor says otherwise.
1. Irritability & Mood Swings
Are you snapping at your family over minor annoyances? Yelling at other drivers? Feeling deep frustration over the news? If you’ve noticed increased irritability or mood swings, it could be due to dropping testosterone levels.
Low T isn’t just about aggression—it’s also linked to depression and emotional instability. Many men describe feeling "off" or not like themselves. If that sounds familiar, it’s time to check your hormones.
2. Poor Sleep Quality
We know that lack of sleep can cause low testosterone—after all, testosterone is primarily produced while you sleep. But did you know that low testosterone can also cause poor sleep?
If you’re tossing and turning, waking up frequently, or struggling to get deep, restorative sleep, your testosterone levels might be playing a role. Research shows that testosterone replacement therapy can improve sleep quality. And if you have sleep apnea, that’s an even bigger red flag for low T.
3. Changes in Body Composition
Less muscle, more belly fat. If your body is changing despite maintaining your usual diet and exercise routine, your testosterone levels may be declining.
Testosterone is essential for maintaining lean muscle mass and keeping fat levels in check. A sudden increase in belly fat or difficulty building muscle could be a clear sign that something is off hormonally.
4. Low Drive—In & Out of the Bedroom
One of the most noticeable symptoms of low T is a drop in drive—and not just in terms of sex.
Low testosterone can also zap your motivation for work, fitness, and hobbies. Many men describe this as "low energy," but it’s more than that. It’s a lack of interest in things that once excited them.
If you find yourself uninterested in sex, business growth, or even activities you used to love, your testosterone could be to blame.
5. High Blood Sugar & Insulin Resistance
This is a big one. If your blood sugar levels are creeping up—whether it’s prediabetes or full-blown type 2 diabetes—you’re at a higher risk for low testosterone.
Insulin resistance (which leads to high blood sugar) and low testosterone go hand in hand. Studies show that men with diabetes often have significantly lower testosterone levels. The worse your blood sugar control, the lower your testosterone is likely to be.
The good news? Optimizing testosterone often helps regulate blood sugar levels, improving metabolic health overall.
Your Doctor Might Say You’re “Normal” – But Are You?
Here’s why symptoms matter even more than a single lab result.
Let’s say your doctor checked your total testosterone 10 years ago and it was 600—a solid level. Now, you’re noticing some or all of these symptoms, so you ask your doctor to retest your levels. This time, your total T comes back at 325.
Your doctor might say, “See, it’s still within the normal range.”
But what they’re missing is that you’ve experienced a nearly 50% drop in testosterone in just 10 years—and your symptoms are proof that it’s affecting your health.
Even if a number falls within a “normal” range, a significant decline is not normal for you. And that’s what matters most.
Final Thoughts: Take Action Now
If you’re experiencing these warning signs, don’t ignore them. Your testosterone levels may be declining—even if your doctor says they’re “normal.”
You don’t have to rely on medications right away. There are natural strategies to optimize testosterone before considering TRT, including diet, exercise, sleep improvements, and lifestyle changes. My clients experience an average 70% increase in total testosterone within three months using this approach.
If you’re ready to take control of your health and performance, start by assessing your symptoms and then get the blood work to back it up.
It’s Totally Possible to Have Optimal Testosterone After 40
Maintaining optimal testosterone levels after 40 is absolutely possible. The key is to ensure your body keeps producing it and that it's available for use.
If your testosterone is low and you’re under 70, it's usually a production issue.
When I tell guys that the natural approach to fixing low T starts by identifying why it's low, they often say, “Isn’t it just my age? I thought low T was a normal part of being over 40.”
While it’s common, it’s definitely not normal.
Take a recent conversation I had with a potential client. He was 67 years old, 40 pounds overweight, and prediabetic, yet his total testosterone was 465 ng/dL. He wasn’t taking any supplements or strength training, so imagine how much more testosterone he could produce if he optimized his health. The point is, this man did not have low T, and he’s almost 70.
However, about 3 in 10 men over 40 do have low T—defined as levels below 300 ng/dL on two separate tests, along with symptoms. So, what’s causing this?
Why Do Men Have Low T After 40?
A large 2023 study looked at the root causes of low testosterone in over 25,000 men. It identified six key factors contributing to low T:
High BMI (overweight or obese)
Low exercise levels
High blood pressure
A history of smoking, heart disease, cancer, or diabetes
Taking statins or psychiatric medications
Marriage
These issues—whether it’s excess weight, inactivity, or prediabetes—are caused or worsened by diet and lifestyle, not simply by age. While this might sound discouraging, it's actually good news because it means you can reverse these factors and restore your testosterone production back to normal.
Think of these problems as kinks in a hose, a dam blocking a river, or a clogged fuel line. Your body is still capable of producing testosterone, but something is stopping it. What I’ve found after helping hundreds of guys with low T is that once you identify and then clear these obstacles, you can maintain T production as you age.
How to Naturally Support Testosterone Production
1. Cholesterol: The Raw Material for Testosterone
Testosterone is made from cholesterol in a process called steroidogenesis, which also produces cortisol and estrogen. If you’re on a statin or have low HDL cholesterol, it can interfere with this process. Your body needs cholesterol, and maintaining a nutrient-dense diet with minimal processed carbs is often more effective than relying on medications to manage cholesterol.
2. The Brain-Testes Connection: The HPG Axis
The hypothalamic-pituitary-gonadal (HPG) axis is the signaling system between your brain and your testes that tells your body to produce testosterone. Think of it like your brain telling you you're thirsty—you get the message, drink some water, and the feedback loop is satisfied.
Testosterone production relies on signals like Gonadotropin-Releasing Hormone (GnRH) and Luteinizing Hormone (LH). Unfortunately, these signals can be disrupted by chronic stress, which prevents your testes from getting the message, reducing testosterone production.
3. Healthy Leydig Cells: The Testosterone Factories
Leydig cells in your testes are responsible for making testosterone. To function well, these cells need to be healthy, but they’re often disrupted by:
Inflammation
Insulin resistance (like prediabetes or diabetes)
Environmental toxins (phthalates, heavy metals, pesticides)
Leydig cells can handle a lot, but when overwhelmed by inflammation or toxins, they stop functioning properly, and testosterone production declines.
4. Vitamins and Minerals: The Building Blocks
Most guys I work with don’t realize how important vitamins and minerals are for testosterone production. For example, low vitamin D levels are associated with low T, and supplementing with vitamin D can raise your levels if you’re deficient. Other key nutrients include zinc, magnesium, and omega-3 fatty acids.
Making Sure You Can Use the Testosterone You Make
Once your body is producing testosterone, the next step is ensuring it's usable. This means having enough free testosterone—the testosterone not bound to proteins like SHBG or albumin. Ideally, about 1-2% of your total T is free testosterone.
To optimize free testosterone, you need to be metabolically healthy. Here’s what that looks like:
Waist size under 40 inches (ideal is half your height in inches)
HDL cholesterol over 40 mg/dL (ideal is 50+)
Fasting blood sugar under 100 mg/dL (optimal is 80)
Triglycerides under 150 mg/dL (optimal is below 100)
Blood pressure under 130/85 (optimal is 120/80)
If three or more of these markers are out of range, you likely have metabolic syndrome, which can significantly affect testosterone. Visceral fat, for example, secretes an enzyme that converts testosterone into estrogen, creating a cycle of weight gain and low T. In extreme cases, this can cause men to develop breast tissue.
This explains why testosterone alone via TRT won’t fix the underlying issue. You need to make sure it's not being converted into something else.
The Three Boxes You Need to Check for Optimal T After 40
Fix what’s blocking testosterone production – Address the factors that are preventing your body from producing testosterone.
Ensure you have the right building materials – Make sure your body has the necessary vitamins, minerals, and cholesterol to support healthy testosterone production.
Make sure the testosterone isn’t being bound or converted – Optimize your metabolic health so you can use the testosterone your body makes.
By addressing these areas, you can maintain optimal testosterone levels—no injections needed—well into your 70s.
References
Marriott, Ross, et al (2023). Factors Associated With Circulating Sex Hormones in Men : Individual Participant Data Meta-analyses. Annals of internal medicine. 176. 10.7326/M23-0342.
Aitken, R. J., Roman, S. D. (2008). Reproduction, 136(2), 173–185. doi:10.1530/REP-07-0582
Dhindsa, S., et al. (2004).Testosterone Deficiency in Men With Type 2 Diabetes. Endocrine Practice, 10(4), 367–374. doi:10.4158/EP.10.4.367
Gray, P. B., et al. (2018). Chronic Stress, Testosterone, and Hypothalamic-Pituitary-Gonadal Axis Dysfunction. Frontiers in Neuroendocrinology, 49, 58–70. doi:10.1016/j.yfrne.2017.12.003
Skakkebaek, N. E., et al. Endocrine Disruptors and Male Reproductive Health.(2016). Nature Reviews Endocrinology, 12(7), 410–424. doi:10.1038/nrendo.2016.57
Prasad, A. S., et al. (1996).Effect of Zinc and Magnesium Supplementation on Testosterone Levels. Nutrition, 12(5), 344–349. doi:10.1016/S0899-9007(96)00049-6
What's a good testosterone booster?
It's amazing how often someone asks me this.
I attribute it to the conditioned response created by years of watching pharmaceutical commercials that claim there’s a simple and easy solution for every health problem.
Low testosterone? Here take this one thing and all your problems will go away.
If there was a true “testosterone booster” supplement you would know about it.
Honestly, TRT is the closest thing we have to a single compound that boosts T as it’s guaranteed to raise your testosterone, because it’s, well, testosterone.
But I don’t think that’s the right mindset to fix your overall health, in the same way I wouldn’t recommend taking Aspirin to relieve pain caused by a rock in your shoe.
Take the rock out.
Instead, you want to make sure your body has everything it needs to make testosterone, naturally.
The right vitamins, minerals, and nutrients to build testosterone on a daily basis.
The simplest place to start is to make sure there's not a nutrient deficiency contributing to your low T, especially vitamin D and zinc. You also want to make sure you're eating the right fats, like whole eggs, since testosterone is made from cholesterol.
After that you can choose a botanical medicine to help correct any underlying causes of low T. I use Tongkat ali, for example when SHBG is elevated and we’re trying to signal to the testes to ramp up production, or Fadogia acrastis if LH is low. There are many other options here.
From there it’s just fine-tuning your lifestyle, and within a couple months you can rely on your body to make enough T.
Is there viagra in your supplements?
A study tracking supplement data for 9 years found pharmaceuticals in 776 different supplements, including products marketed for sexual enhancement, weight loss, and muscle building.
Viagra was in the ED supplements, sibutramine in the weight loss supplements, and, get this, synthetic steroids were in muscle building supplements.
20.2% of the products studied contained more than one unapproved ingredient.
I'm not sharing this data to scare you away from supplements, but I do want to scare you away from cheap, low-quality supplements.
How can you tell if a supplement is high quality or not?
The most obvious test is to look at the name, and avoid products with unscientific words like "boost" or "max" or "shred."
It's may be true that supplements, unlike pharmaceuticals, are not approved by the FDA for effectiveness or safety, but that just means it's up to you to figure out if the ROI is worthwhile.
That doesn't mean, however, that all supplements are a total free-for-all.
Supplements don't need approval before they hit the market, but there are still systems in place to help promote the companies who are making high-quality products.
If a company is GMP registered it means they observe Good Manufacturing Practices which was specifically established for the supplement industry, and includes things like ingredient testing.
Similarly, if a supplement brand is NSF registered it means they agree to annual audits and periodic retests of each supplement they produce.
NSF also has "NSF Certified for Sport" which screens supplements for 280 substances banned by most major athletic organizations as well as undeclared ingredients including stimulants, narcotics, steroids, diuretics, beta-2-agonists, masking agents and other substances.
It's nice to know my creatine doesn't contain steroids.
My top 5 rules for supplements:
Rule #1: If you're going to put it in your body everyday, buy the highest-quality product you can afford.
Rule #2: Cover your bases first. Vitamin D, magnesium, fish oil, a multivitamin, and a multimineral. Also, creatine (without steroids) if you're resistance training. Then experiment.
Rule #3: Take your buddy's advice with a grain of salt. There's a spectrum of evidence when it comes to what you need to do to improve your health. Your buddy's advice is low-quality, a doctor on a podcast is medium-quality, and a doctor who makes personalized recommendations for you is the highest quality.
Rule #4: Stick to single ingredient products to ensure you're getting a therapeutic dose. Many supplements, especially related to testosterone, have 10+ ingredients which means that each ingredient is too low of a dose to be effective, or you need to take 10 capsules daily which makes it too expensive.
Rule #5: If the product is made by an influencer then it's probably low-quality (IE not NSF-GMP registered, multiple ingredients, low dose, steroids, etc.)
The top 4 brands I recommend the most often:
Pure Encapsulations, Nordic Naturals, Thorne, and Integrative Therapeutics.
Notice how all their products have boring labels, and boring names, yet they're 3rd party tested and high-quality doses.
It makes a difference.