Syntheroid Review

It seems that for every good testosterone booster that is found, there are dozens of not so good ones.

This can be frustrating.

When you discover your energy levels plummeting, or sex drive free falling you don’t want to waste time trying out multiple supplements before settling on a good one.

You want to find out what works, and what doesn’t.

This unbiased Syntheroid review will help you make an informed decision about whether or not it’s the right option for you and hopefully, save you time and money in the process.

Syntheroid is an all-natural testosterone booster, manufactured by XPI (Xtreme Performance Innovations), and claims to be the number one trainer and doctor approved testosterone booster on the planet!

Among its claimed benefits are:

  • Increasing strength and muscle mass
  • Enhancing sexual vigor
  • Increases energy levels

Pros Of The Supplement

  • All-natural formulation
  • Ingredients are clearly disclosed on the product label, adding a degree of trust.
  • Appears to have been on the market for a number of years, so it is fairly well known.
  • Reasonably priced for a month’s supply of the supplement (180 capsules sized bottle)
  • The manufacturer has a marked presence at their official website (even though Syntheroid cannot be purchased there any longer).

Cons Of The Supplement

  • Appears to have been superseded by a newer version on the official manufacturer’s website
  • Has an “official-looking” website that is most likely fake, since after reading the actual description of the product on that page it was clear they were referring to the newer version quite often.
  • Appears to depend heavily on one primary ingredient.

Who Is Syntheroid For?

XPI prides itself on being a supplement manufacturer for bodybuilders and other athletes that strive to improve athletic potential and performance.

In addition to this, however, is the fact that it is likely to improve energy levels and sex drive in the process, which means that even if you are just trying to get in shape it would be of benefit to you.

However, regardless of the claims a supplement manufacturer makes, it is my job to analyze them and let you know how effective they are based on scientific evidence. It is common practice for supplement manufacturers to market aggressively in an effort to compensate for subpar products.

In addition to its ingredients, is the overall reception the supplement receives from customers who have consumed it in the past. If after analyzing reviews it is clear that many people are dissatisfied with the results gained, chances are it won’t do much for you either.

On the other hand, products with stellar reputations are likely to work for a broad cross-section of people and are often worth their price.

Syntheroid Ingredients And Dosage

The good thing about Syntheroid is the fact that you can clearly find dosage instructions all over the web; they make no qualms about letting you clearly know how much you need to take.

The label advises that you take three capsules twice daily; once before breakfast, and the other three before dinner. The only difference I observed between this product and others with similar ingredients is the fact that most of them recommend consumption along with a meal, while Syntheroid recommends that you take it before.

Although this isn’t clearly stated, I believe this to be due to absorption issues, which may be affected by food.

Let’s have a look at the actual ingredients contained in Syntheroid now:

D-Aspartic Acid

If you have been following the blog for a while, by now you probably know that D-Aspartic Acid is my number one recommendation for naturally increasing your testosterone levels as it works for a significant number of men that consume it.

Its results aren’t based on anecdotal reports either, as numerous studies have found that it can elevate levels of luteinizing hormone and testosterone in both healthy and infertile men, in a very short amount of time.

One study found that men given 1.6 g of D-Aspartic Acid per day over the course of 20 days were able to increase sperm volume by 50% [1], in addition to notable increases in luteinizing hormone and testosterone levels.

Another one of the most notable findings from D-Aspartic Acid consumption was a staggering 42% increase in testosterone levels after daily consumption of 3.2 g of the supplement, in just 12 short days [2].

These effects are generally replicable and is one of the reasons why we hold this amino acid in such high esteem.

Fenugreek Seed Extract

While fenugreek seeds have been used for centuries in Indian and Asian traditional medicine, their penetration into the Western supplement market has not been very well accepted, since many manufacturers make exorbitant claims that the herb simply does not live up to.

Manufacturers that include fenugreek in their products do so on the premise that it can increase testosterone synthesis, and while a few studies have shown this it is important to note that these studies were sponsored by companies with an interest in financial gain from showing its efficacy.

This means that chances are high the studies were not carried out in a neutral environment, but rather one that may artificially skew results to show significant benefit.

Other studies have found that it had no effect on free or overall testosterone levels [3] but did inhibit the production of testosterone’s androgenic metabolite, DHT [4]. Another study yet found that it has anti-thyroid effects, which means that your metabolism will slow down and you will gain weight. Not exactly what you were after right?

Last but certainly not least, is the most important finding to make note of – that fenugreek is a galactagogue [5] which increases prolactin secretion. Prolactin is a hormone that triggers the production of breast milk, so while production of milk is unlikely to occur in men, what can happen is the growth of glandular tissue around the breasts, which is known as gynecomastia.

Added to the fact that prolactin is a known dopamine inhibitor, the only thing I can see this ingredient doing is hampering your testosterone enhancement goals, killing your motivation and sense of well-being, and making you grow man boobs. Sorry, hard pass on this one!

Tribulus Terrestris

Ah, no complete testosterone booster would be worth its weight if it didn’t include the legendary Tribulus Terrestris right? Wrong! Even though Tribulus Terrestris was held in high regard 50 years ago, today we know better, and even though it paved the way for the dozens of other effective ingredients we have now, Tribulus Terrestris will not improve testosterone levels noticeably [6].

It may be of modest benefits to older men in poor health with low testosterone levels who stand to benefit from even the slightest intervention. Besides this, if you are fit, work out often, young and generally looking to make a good body even better [7], Tribulus Terrestris is not a good investment.

Horny Goat Weed

One thing I notice too many people have been confusing as of recent is the belief that horny goat weed and MACA are the same things. They are not. Horny goat weed is native to the Asian Mediterranean regions and has been used in Chinese traditional medicine for a number of centuries.

In terms of testosterone boosting potential, at best horny goat weed only possesses mild activity, and that is not even via a direct mechanism. What do I mean by this? Horny goat weed has been shown in studies to have mild cortisol suppressing actions [8], which then translates to improvements in testosterone values.

That aside, horny goat weed is very effective as a pro-erectile aid, being able to improve blood flow and support the growth of new nerve endings in the penis, which is massive for men looking for natural male enhancement supplements.

Other than this, horny goat weed can also help to increase the production of nitric oxide [9] via increasing the production of the enzyme nitric oxide synthase. None of these directly improve testosterone, but by observing improvements in their sex life, most men tend to believe their testosterone levels have skyrocketed.


MACA, gentlemen is believed to be horny goat weed’s long-lost brother, separated at birth and migrated to Peru, where it is native today. Not surprisingly, this is why MACA is known as Peruvian ginseng, but regardless, it doesn’t do anything for your testosterone levels.

Don’t get me wrong, it is an amazing adaptogen and worthy of being called a superfood, as the  concentration of nutrients found in it is far higher than many better-known superfoods.

But back to why it’s not a good testosterone booster; a study was conducted and found that Maca improved libido and erectile quality in a wide cross-section of men, including those that were afflicted by antidepressant induced erectile dysfunction, to super athletes [10] and even normal healthy men. Naturally, supplement manufacturers tried to bend the truth and instead proclaimed it to be a testosterone booster with massive potential.

Further investigation found that it had no effect on hormonal parameters, including luteinizing hormone, testosterone or DHT, but works via a non-hormonal mechanism [11]. So, if you are looking for an effective aphrodisiac, this will work, but it will do nothing for your testosterone.

Tongkat Ali

While Tongkat Ali can be helpful under a certain set of circumstances, it is in no way essential to the overall success of a testosterone boosting supplement. For instance, studies conducted have found that it works wonderfully in older men that have low testosterone levels [12], or helping to buffer the effects of high cortisol levels, while other studies have found that it does absolutely nothing.

If you are a young man in good health, consumption of this ingredient is likely to yield no benefit; if however you are older than 35 and suspect you have symptoms of low testosterone, it may help to address the problem a little.


Boron is a trace mineral that the body needs to help carry out many biological functions, and one that we are often deficient in without even knowing it.

In terms of testosterone elevation, boron does play a role [13], but its efficacy depends on the amount consumed and how long it is taken for. Studies conducted using low doses over the short-term have not shown much promise when compared to it being used for a longer period of time.

The bottom line when it comes to boron is probably this; it can’t hurt to use it, but at the same time don’t expect it to work fast or to an extent that is highly noticeable.


Bioperine is basically black pepper extract, included in many supplements to aid the absorption of other ingredients.

The addition of this ingredient could also explain why the manufacturer recommends that you take it before meals, as its absorption will be less dependent on food (especially carbohydrates and fats).

Results From Users

While grainy photos were normal back in the day, it brings into questions how long this transformation really took, or if the supplement was the sole driving factor.

Syntheroid appears to have mixed reviews from those who have used it, with some claiming good results and others not having anything to show. This is a fair indicator that the product is genuine, as not everyone is expected to respond to a supplement exactly the same.

As we analyzed, many of the ingredients seem more suited for male enhancement and libido, and not necessarily testosterone elevation.

Syntheroid Side Effects

Being an all-natural supplement there aren’t many expected side effects. However, owing to the presence of D-Aspartic Acid, a slight degree of some stomach discomfort is possible as it is being absorbed. Other than this, keep an eye on overall breast tissue, as if you notice any increase in the glandular tissue, it probably means that fenugreek is exerting a very strong prolactin effect.

Summary – Does Syntheroid Really Work?

Based on my analysis of the product ingredient profile and user feedback, it will possibly help you a bit in your quest for muscle, strength and sexual enhancement. However, I believe that only the D-Aspartic Acid is really worth its weight and will directly increase your testosterone levels. Many of the secondary ingredients are better suited for male enhancement products, with fenugreek being questionable altogether.

Reviews are mixed, which is fair, but there are favorable ones as well. It is priced affordably, at $55-$60 for a month’s supply, while many other competing products may run you into an excess of $100.

Where To Buy Syntheroid?

The safest bet when purchasing Syntheroid is from the trusted  Even though I mentioned there is a website purporting itself to be official, I strongly believe this to be a fake one as the manufacturer site is a separate entity. Get yours from Amazon and you can rest easy knowing that you can be refunded in the event you get a counterfeit product.