Update 3/17/21. When I first heard the name Syntheroid I thought it was a supplement for the thyroid because its name sounds a LOT like the drug synthroid that people take for hypothyroidism. But Syntheroid is billed as a natural testosterone booster whose motto is “power, mass, sexual performance.” The makers of Syntheroid claim that it can improve speed, agility, and reaction time, as well as muscle size and strength. This is in addition to the claim that Syntheroid can maintain libido during hardcore dieting. These are all pretty bold statements so I'm not surprised if people wonder if Syntheroid really works or not? Let's now review Syntheriod and what can be discovered. Also see my review of the HGH supplement, SeroVital.
Who Makes Syntheroid?
When I checked the product website – syntheroid.com -I couldn't find out who makes this product. It's only after some digging that I discovered that syntheroid is made by a company called XPI (xpisupplements.com).
The address of XPI labs is 965 N 1430 W Orem, UT 84097. The link provided is to show what the area looks like. I see a lot of warehouses. I did not see any building called “XPI laboratories” but since most of the buildings appeared dull looking – built for function, rather than looks – I'm sure it's in there somewhere. XPI labs do not seem to have a BBB listing when I checked on 12/7/11.
On the Syntheroid.com website, there is a video of a 31-year-old man named Josh Dahl (“The Josh Dahl Story”) where he says that Syntheroid makes him feel like he's 21 years old again. They listed his name like we should know who Josh Dahl was – which I didn't – so I did some goggling on who Josh Dahl, was but could not find anything. Maybe Syntheroid did do what Josh said but in general, I take all testimonials from people I do not know with a big grain of salt.
Syntheroid Ingredients
Kudos to the Syntheroid website because they do tell us what's in this product. If you take 3 capsules of Syntheroid -the recommended dose – you get the following:
| Tribulus Terrestris | 650 mg |
| Testofen | 300 mg |
| Aminogen | 250 mg |
| Coleus forskohlii | 125 mg |
| Milk Thistle | 120 mg |
| Alpha lipoic acid | 100 mg |
| Eurycoma Longifolia | 100 mg |
| Horny goat weed | 100 mg |
| Bioperine | 15 mg |
Remember, even though the name syntheroid sounds like a drug, syntheroid is not a hormone or a pro hormone. It's a dietary supplement. They even say this on the Syntheroid website.
Looking over this list of ingredients, Syntheroid has some things found in many other products I've reviewed in the past.
For example, Syntheroid has Tribulus. I know people have said that tribulus works for them but I have been skeptical about the claims of this herb since the 1990s when it first started getting popular. For more on this, read the Tribulus review.
Despite the hype about Tribulus and testosterone, I can't find any proof that it works. For example, in a study published in 2001, Tribulus didn't work. In another study from 2007 tribulus didn't work.
If anybody knows of a“tribulus raises testosterone study”, please let me know and I will happily update my reviews on this herb.
Now, no study is perfect, so if you really want to know if tribulus raises testosterone, get your doctor to check your testosterone before starting tribulus (or Syntheroid) and after a month of using it. This is the only way you can know for sure if it worked or not.
As for Testofen, it's a cool-sounding name and was likely invented to give the impression that it raises testosterone – but it doesn't. Testofen is just a made-up name for the herb Fenugreek. For more on fenugreek- testosterone research also see the review of Ageless Male.
Fenugreek might raise insulin levels. Since insulin helps us use amino acids, that means it has a mild anabolic effect. I'm guessing this is why it's in a testosterone booster supplement. Here is Fenugreek on Amazon.
Ironically, this effect on insulin is why fenugreek is also found in diabetes supplements. For example, the diabetes supplement Glucotor V2 also has fenugreek. In fact, this diabetes supplement has the same amount of fenugreek – 300 mg – as Syntheroid does.
Aminogen
The Syntheroid website says that Aminogen is a ” proprietary proteolytic synthetic enzyme” that “was created to improve protein digestion and absorption.” That means at that Aminogen is not an amino acid supplement but rather just a fancy name for a protein-digesting enzyme supplement.
Unless you have a problem absorbing protein you don't need enzyme supplements. They say that Aminogen “works to produce a higher bioavailability within your body, particularly to your muscles.” So, where is the proof of this? As far as I can tell neither Aminogen – or Syntheoid – has any peer-reviewed clinical proof that it does anything. Since they can't prove to me that this statement is true, I discount it.
Just a heads-up, animal protein – has a very high absorbability, so unless your doctor has told you that you have a problem with digestion, you don't need any supplemental digestive enzymes. What's a good way to remember animal protein? It's any food that had a mother. That's how I remember it!
Coleus Forskohlii
This herb is said to be a metabolism booster and weight loss supplement. The idea here is that coleus forskohlii (forskolin) stimulates fat-burning enzymes that help us lose weight. One small study of older, overweight men also noted that coleus forskohlii increased testosterone levels.
This is the logic why Coleus forskohlii is found in many weight loss products such as Lean and Fab and Apidexin to name a few.
Here is coleus forskohlii on Amazon.
The problem with coleus forskohlii research is that they often have problems and so for the moment, I will keep an open mind about forskolin until better research is done. For more on this research, read my Coleus forskohlii review.
Milk Thistle
Since steroid abuse is thought to damage the liver, and since Syntheriod is reputed to be a testosterone booster, I'm guessing this is why they added the liver-protecting supplement -milk thistle – to Syntheriod.
That is the most obvious answer I can guess because there seems to be no clinical proof that milk thistle raises testosterone or improves libido. There is interest in milk thistle for diabetes because it has been shown to reduce blood sugar levels.
Might stabilizing blood sugar levels help people have better workouts? In theory, maybe. This might be another reason for putting milk thistle in Syntheroid.
Mostly this herb is an antioxidant and one of its active ingredients is a compound called Silymarin. Syntheroid has 120 mg of milk thistle but I can't tell from the product website how much Silymarin this translates into.
Alpha Lipoic Acid
Like milk thistle, alpha-lipoic acid has also been researched for its blood sugar-lowering effects. I've seen this stuff used in many exercises and weight loss supplements despite any good proof it helps weight loss or exercise.
For example, alpha-lipoic acid is also found in the bodybuilding supplement Stemulite and Jillian Michaels Fat Burner as well as the Plexus Slim weight loss supplement.
Like several other ingredients in Syntheroid, eurycoma longifolia is found in a variety of other products. For example, this herb is one of the main ingredients in TriVerex – a male enhancement product you may have seen on late-night TV.
It's probably eurycoma longfolia – as well as horny goat weed – that is at the heart of the claims that Syntheroid improves sex. I don't want to reinvent the wheel on these ingredients, so please read my words on TriVerex” for more info on the research behind both Eurycoma longfolia and horny goat weed.
The same thing goes for Bioperine. For more on this ingredient see my Lean and Fab review.
Syntheroid Side Effects
I think if you are healthy you might not notice any side effects with Syntheroid. If you are not “healthy” or take any medications, see your doctor first. Syntheroid is probably very safe in healthy people but as far as I can tell this assumption has never been tested. Here is Synteroid on Amazon for those who want to check out the comments from others who have used it.
One older study noted that alpha lipoic acid might lower thyroid hormone levels. If this holds true, it might also reduce vitamin D levels as well as metabolic rate. I'm not sure if this “side effect” is true or not but it's worth mentioning just in case you have hypothyroidism. Alpha-lipoic acid might also add to the effects of insulin and other diabetes drugs.
Fenugreek might cause hypoglycemia (low blood sugar) and interact with insulin or other blood sugar-lowering medications. It might have an even greater blood sugar lowering effect when combined with alpha-lipoic acid.
Milk thistle might interact with many medications like coumadin (a blood thinner). The herb might also have an estrogen effect that might be bad for women with a history of breast cancer. This effect is probably a long shot, but speak to your doctor if you are not “healthy” just to be safe.
How Much Does Syntheroid Cost?
They say 1 bottle currently costs $59.95 on the Syntheroid website. I think that is a lot of money for a product that has zero clinical proof that it works.
Here is Synteroid on Amazon to compare prices.
Does Syntheroid Work?
On the XPI labs website, they say that Syntheroid “was scientifically formulated to boost testosterone levels, improve protein synthesis, absorb nutrients, and burn fat faster than any other legal supplement on the market.” Scientifically formulated? How did they scientifically formulate this product but did not conduct any scientific tests to prove Syntheroid actually does what they say?
In my book, you can't invoke the name of the mighty god science (lowercase g) without doing actual scientific testing – in humans. Failure to do so is just bad science. They also say that with Syntheroid, you can boost testosterone by up to 400% but proof of this cannot be located.
If you are interested here is Synteroid on Amazon.