Hands up if any of the following describes how you feel or look lately: Your energy and vitality have been drooping; you've seen an unexplained increase in body fat ("What's that inner tube doing under my shirt?"); you've lost muscle mass and/or strength; you have less endurance than usual; the best way to describe your libido would be "nap time at a nursing home."

If you raised your hand at least twice, you may have a deficiency in human growth hormone. Nicknamed the "wonder hormone," human growth hormone—also called GH or HGH—is a peptide hormone that's produced in the pituitary gland at the base of the brain and plays a crucial role in everything from body height, brain function, and skin health to bone density, fat loss, and muscle growth.

Unfortunately, GH production peaks shortly after puberty, then goes on a steady—and, sometimes, rapid—downhill slide from there.

Let's find out if you're being shorted (so to speak) in the GH department, and nail down everything else you need to know about the hormone.

Why human growth hormone is such a big deal

As its name implies, GH is responsible for cell growth and regeneration. It's crucial for building muscle mass and bone density, but it also plays a major role in keeping all human tissue healthy, including that of the brain and other vital organs. It can even boost your sex drive.

When secreted, GH stays active in the bloodstream for mere minutes—just long enough for the liver to convert it into growth factors, the most crucial of which is insulin-like growth factor 1, or IGF-1. The main driver of tissue growth, IGF-1 synthesizes amino acids and metabolizes fat and protein, which build muscle and burn fat.

In short, if you're not hacking it performance-wise, GH could be the culprit.

How you can determine where your HGH levels fall on the spectrum

Clinical tests are needed to confirm a GH deficiency, but our short quiz can give you an idea of your levels right now. If you find they're low, there are various lines of attack you can take:

For one, work on improving your sleep quality—it's then that your body secretes the highest amount of growth hormone. 

After that comes exercise. A review of studies published in the journal Sports Medicine found that HIIT and resistance training stimulate GH production.

What you can do to kick up your HGH levels

Whether you're hoping HGH will help you muscle up, slim down, sleep sounder, or get it on better, an efficient way to raise GH levels is with a supplement like Growth Factor-9.

Made by Novex Biotech, Growth Factor-9 is the only growth hormone supplement clinically tested to increase serum GH up to 682% in two hours. This complex GH antecedent contains a patented ratio of growth-hormone-stimulating ingredients extensively vetted by researchers at a top US university. What's more, it's backed by four clinical trials and 13 U.S. patents.

What makes it so effective? A highly specialized ratio of critical GH-building ingredients. See, the only way to directly add more GH to our body is by injection, which is illegal in the US without a doctor's oversight and costs thousands of dollars. It's often abused in this way by athletes trying to gain an edge or celebrities trying to stave off the horrors of aging.

But you can naturally up your GH by supplementing with certain precursors that stimulate secretion of the hormone—they include amino acids like glutamine, lysine, and ornithine. But the timing of taking these aminos, along with the amounts, is crucial and hard to follow faithfully. Growth Factor-9, however, eliminates all of the guesswork. Packed with a proprietary combo with potent precursors, the formulation is easy to use and effective.

Take Growth Factor-9 before bed on an empth stomach. Combined with regular workouts, it can help turn your body into a GH-making machine. You may just find yourself looking and feeling younger, stronger, and more energized.

Growth Factor-9 is available at your local VitaminShoppe or GNC, or buy online at growthfactor9.com.