Spartagen XT ingredients are eleven in number (as shown in the preceding image). But they can be classified into five subgroups as: roots, herbal leaves, fruits, vitamins and minerals. And, (as I explained below) science shows that these ingredients are naturally effective for improved male performance.
Of course, Spartagen XT ingredients got scientific validations largely because researchers often work round the clock to unlock more nutritional and medicinal values of various herbs. And this progressive work has been going on for ages.
For example, Benzie Iris FF, and Sissi Wachtel-Galor, in their book on "in-depth scientific examination of effects of individual herbs", said that:
“Herbal Medicine is a growing field with many traditions” .
And, according to the University of Michigan Medical Center :
“... herbs can help treat a variety of conditions, and in some cases, may have fewer side effects than some conventional medications” 
Thus, the rise in scientific validations of herbal medication is leading to higher consumer interest in herbal solutions. In fact, herbal products are now the preferred dietary supplements for many Americans. However, the rising interest in herbs is also driving more clinical research and scientific studies on herbal compounds. Basically, it's like a a sequence of reciprocal cause and effect. And, as it stands, many scientific evidences show that these natural ingredients are quite safe and very effective.
Yes, several scientific evidences show that herbal ingredients can improve men's health significantly. But it's also clear that some environmental factors (such as soil quality, prevailing climate condition or bugs) can enhance or damage the quality of any herbal ingredient. For that reason, plenty of scientific work is needed in order to select, purify and standardize these ingredients for safety and maximum potency. This is where Edge Bioactives (the manufacturer of Spartagen XT) comes in.
Spartagen XT ingredients: The selection, purification and standardization process
Edge Bioactives has an elite assembly of senior scientists here in New Jersey, United States. The job of these scientists is essentially to uphold the premium quality of Spartagen XT, regardless of financial costs. And for that reason, no expense is considered too much when it comes to selecting, purifying and standardizing these ingredients. On the contrary, the Spartagen XT advanced testosterone formula is made with the purest blend of the natural ingredients shown below.
Here's, a table of references used on this page. These references point to relevant scientific papers and expert opinions. And they all support the effectiveness of various ingredients that make up the Spartagen XT formula. However, below is a description of the five groups of those ingredients and their eleven specific components.
Spartagen XT Ingredients - GROUP 1: The Roots
Basically, we have four Spartagen XT ingredients in the roots group.
1) Tongkat Ali Extract
Research shows that the root of Tongkat Ali contains some compounds that naturally increase the release rate of “free” testosterone. . Additionally, evidences also show that this natural increase on the body’s release of testosterone is quite effective , results to higher libido  and actually boosts the quality of semen .
2) Maca Roots
Scientific evidence shows that Maca (an historic Peruvian medicinal plant and food-supplement) contains nutritional properties that can enhance energy and fertility. In fact, a double-blind, randomized study shows that Maca root can boost libido in men  and alleviate sexual dysfunction . It can also help to maintain hormonal balance .
3) Butea Superba Extract
Butea Superba is an historic Indian plant used traditionally to manage male sexual disorders. Research shows that this plant can improve semen production, decrease defective sperm, and very useful in alleviating male infertility .
4) Asian Ginseng Extract (whole plant)
Generally speaking, Ginseng is known to enhance libido and boost sexual performance in men . However, a number of scientific studies have also shown that the roots and berries of Korean Red Ginseng in particular (also known as Asian Ginseng) can boost erection  and help to alleviate erectile dysfunction .
Spartagen XT Ingredients - Group 2: The Herbal Leaves
There's only one Spartagen XT ingredient from this group, and it's called:
Scientific studies show that Chrysin inhibits testosterone to estrogen conversion . Simply put, it helps to improve vigor and vitality. Thus, Chrysin contains a flavone that promotes hormonal balance for body building.
Spartagen XT Ingredients - Group 3: The Fruits
Actually, there are two Spartagen XT ingredient from this group. But that's in addition to the Ginseng Berries (which I mentioned earlier). Here's the second fruit:
- Tribulus Terestris
Tribulus (also known as puncture vine) is an historic fruit-bearing Mediterranean plant. Some extracts from its fruits can enhance athletic performance, promote heart and circulatory health and help solve sexual issues . A clinical study of Tribulus also showed that it functions as Adaptogen  and helps to alleviate “low sperm count” effectively .
Spartagen XT Ingredients - Group 4: The Vitamins
We have three Spartagen XT ingredients in the Vitamins category:
1) Vitamin D
In actual sense, the body naturally produces Vitamin D when you're exposed to sunlight. Thus external vitamin D supplements are usually a precursor for the vitamin D hormone. But, due to the limitation of source, Vitamin D deficiency (which is linked to depression and terminal diseases) is rampant around the world . Good news however is that Spartagen XT contains this essential element. And it helps users (especially men) to develop strong bones, robust immune system, and positive mood , , .
2) Vitamin E
Vitamin E helps to prevent muscle damage. In fact, some researchers believe that it’s quite useful for physical performance and strenuous endurance exercises. It also normalizes the function of immune cells and helps to ensure a healthy heart. In addition, it aids blood circulation and helps to ensure safer and beneficial physical exercise and bodybuilding , , .
3) Vitamin B6
Spartagen XT Ingredients - Group 5: The Minerals
We have two Spartagen XT ingredients in the Minerals group.
1) Zinc (as zinc oxide)
Magnesium is critical to the body and how it functions. It normalizes blood pressure and regulates the heart rhythm. Additionally, it participates in energy production, aids protein formation, and promotes healthy immune system. Magnesium also normalizes muscle and nerve function, and helps to strengthen the bone. , , , ,  , , , , .
Clearly, Spartagen XT ingredients contain a healthy amount of all the nutrients listed above. Of course, as earlier mentioned, the FDA has not verified this claim. But the effectiveness of each ingredient used in the Spartagen XT formula is supported by a clear scientific evidence as shown in the references.