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.
Hi Joe:- What about that rub on clear stuff, which is applied under the arms, or on the shoulders? I’m trying Androgel 1.62%. I use one pump, applied to one upper arm/shoulder area. Supposedly, this amount (one pump) of application provides 20.25 mg of testosterone. To be quite honest, I haven’t felt anything one way or another.
I did have my T levels checked before starting, because my doctor would not prescribe it without first getting the test. He said I was a little low for a man of 63. I’m on my 2nd bottle. I can say one thing for sure, this is not an inexpensive endeavor for a self pay uninsured person. But it is a lot less expensive than fancy meals, parking fees, meal tips and champaign to apply before taking the “plunge”. It works just as well as all that stuff, and it’s less time consuming as well. I have not had my T level checked again. Thanks Joe – scotto
Scott, others have also told me that they don’t feel any different when they use Androgel . Things don’t have to be felt to do something. Let’s see what your next blood test says.
Hello Joe. First off I think this is the first lengthy blog I have ever made it through because it usually gets out of control by negative people feeding off each other. I have had the chance of being in good shape going all natural with just foods and exercise as well as using pills. This was also at 2 different times. I was in great shape using nothing. I was at 5 9 150lbs then went all the way up to 212 lbs withing 2 years and then repeated that twice in the last 5 years.
I played a lot of sports and know a lot of the tricks to have fast weight gain as well as loss. Which this is not the healthy way to do it. Take if from my experiences with this in my life. If you want to increase your muscle super fast there is no healthy way. I know guys that look to be in the best shape possible with out of control cholesterol levels. The healthy way is to eat NON PROCESSED FOODS AT ALL EVER!!!! Which is very hard to do in this country seeing as most foods sold here are processed now.
The second thing to do is build up exercises which means don’t go by reps. When your working out as soon as you start to hurt especially your back stop immediately and do static stretching. Now if you don’t care about the long term and you want results now I have a way to look better fast.
For breakfast have an 8oz glass of ANDERSON ERICKSON CHOCOLATE MILK. If they don’t sell that where you live get one with no fructose corn syrup and made with real coco. Then for lunch a have 10oz whey protein shake ( they are all basically the same) with one banana. Make sure to eat it and not blend with shake. Then exercise literally right before you eat dinner and have an 8oz whey protein shake waiting for as soon as your done.
Then for dinner have white rice with chicken THAT’S IT NO SEASONING OR SAUCE!!!! At this time eat whatever you need to feel full. Since its not seasoned and doesn’t taste as good your brain will not want to stuff yourself. The only other thing along with this is DRINK WATER ALL DAY PERIOD!!
I promise you if your trying to get rid of body fat fast I have used this method for over a decade. Thanks for your time and I know that was long lol. Oh yeah if absolutely need a supplement I would go with a L-Arganine with a caffeine pill.
Lucus, thanks I’m glad you found my site and were able to get through the lengthy posts 🙂
Joe thanks for saving me some $$$!! I’ve been taken nature made liquid T booster I get at Vitamin Cottage. Its $30 for 30 servings and all I take is one a day. I’ve found that taken this along with a ZMA supplement and Glutamine has worked great for me. How these companies in the supplement market can get away with selling BS is comical! Again, peace bro for saving me $$$ on garbage like Syntheroid!
Chris, your very welcome. glad you found me 🙂
Hi guys, I found this website just over 6 weeks ago when I was researching Syntheroid. I found the site after I had ordered Syntheroid. I’m lucky that I have an uncle who is a doctor so I fort I would try it and get test levels tested
I’ve taken Syntheroid an guess what I’ve had my test levels tested before and after as my uncle is a doctor.
My test levels are classed as “normal” by a doctor but “normal” to a doctor means not unhealthy. These words came form my uncle himself. He did say mine were slightly low if he went on averages.
Anyway I took Syntheroid for only 4 weeks (because I found sleeping hard), took 6 tabs a day, 3 An hour after breakfast and 3 an hour after dinner. I normally find this is the best time to take any supplements.
I did notice I had more energy when working out but I normally use N O explode and this give you more energy also.
My sleep was strange, the days I didn’t work out sleeping very hard. I only work out 3 or 4 times a week.
I definitely needed a lot of water, even in the night I would wake up for a drink which I’ve never done before. Back to test levels.
My test did raise slightly, and when I say slightly I mean very slightly. I don’t no anything about science but this is what my uncle wrote down so I could do this review.
Measurements in (ng/dl)
Before I took Syntheroid, test level 632.
After 2 weeks of Syntheroid, test levels 636.
After 4 weeks of Syntheroid, test levels 638.
I told my uncle why I was doing this and he told me that this slight increase might not be due to the supplement I was taking.
Hope this helps.
Im going to try Tongkat in about 8 weeks time so I will try get back to you on that aswel.
A special mention for Joe as well, this website is amazing and thanks for taking your time to do it.
Grams may be bad but I’m on an iPhone.
Josh, thanks for going to all that effort to get your testosterone levels measured!
Hi! To be short: The only real ways to boost testosterone levels in order to have a significant impact on condition and metabolism are not legal. End of story. Feeling an effect (e.g. erections, dynamism, etc.) might exist (although often generated by placebo) but has no serious impact on the quest for anabolism and muscular growth or performance. Hard to digest for want to believers I know. Results? Go invest in quantity of QUALITY FOODS coupled with SERIOUS training.
Hi, I am 45 and had my T levels checked over a month ago, by a urologist that has a focus in T level treatment.
My level was about 380 ng/dl, which is considered very low normal. My doctor prescribed the drug Clomid, which increases an enzyme which increases Testosterone. After two weeks of a few continuous side effects (sleep difficulty, no sex drive or erections) I decided to stop the drug.
My doctor then prescribed Amiridex, which increases T by converting estrogen to T. I decided not to take it because there is a high incidence of bone fractures and joint pain. No thanks.
Anyhow, both of these drugs, covered by most insurance plans, work for most people, which studies have proven. You can increase your T by approximately 150-300 ng/dl for both.
I may try the Clomid again, as the side effects I received may have been due to other causes, and perhaps the drug had not taken effect yet.
I think the supplements are crap, although I do take ZMA because it gives me good night erections and I think helps me to sleep better.
Hey well seems like you know quite a bit so what
Do you think about pre supplements and proteins??
Is there certain brands or ingredients to be lookin for? Especially in pre supplements… I’ve tried a couple and they seem to work at first then I just can’t get the same amount of energy and focus? What would you prefer on everything except for these t boosters? Thank you!
Hi Austin, for preworkout supplements I’d say just have some carbs and protein about 1-2 hours before working out. A lot of pre-workout supplements contain caffeine (because of the kick it gives you) so think about that if you want a little extra kick.
As for proteins, I like whey and casein protein mostly overall. Aim for at least 20 grams of protein (with a few carbs) after exercise also.
im nathan. i know for a fact test boosters work. a friend of mine took unleashed and in one month he went from benching 200 to 245. and he had the symptoms of high T including a lot of body acne and a slight change in temper. so i think that just because something isn’t proven to work it doesn’t mean its proven not to work. so before you go badgering products make sure you have enough research to disprove it or your making the same mistake they are
Nathan, thanks for writing. I am not trying to badger anybody. I just want to provide the facts so people can make a more informed decision. Just to double check again, I just went to syntheroid.com where they say its the “worlds most powerful testosterone booster” – yet they dont show any proof that it really boosts testosterone. If they make this bold claim dont you think they should prove it? Where is the research showing it raises testosterone levels in people? I looked and didn’t see any research/ proof presented on the Syntheroid website.
I’m glad your friends bench went up, but that does not prove his T levels increased. Same thing goes for him getting acne and having an increased temper. Its an interesting coincidence but until we do a blood test, how do we know its not just a coincidence? Blood tests for T levels are cheap – they only cost about $50.
I have to be a skeptic about this Nathan because people deserve to have faith that products they use really do what their clearly crafted advertisements claim they do. Testimonials alone dont do that. If XPI does research showing syntheroid raises testosterone levels in people, I will be more than happy to update my review with that new information.
I’m still waiting for somebody to show me their blood tests before and after using a testosterone booster (any T booster supplement) to see if it really works.
I’m 64 and without any BS i look better than most guys in their 20s. I been traing for for 45 yrs, with just good diet ass busting workouts and creatine after my workouts. All that other crap you can throw out the window and save some money.
Thanks for your article Joe. Is there a certatin T booster that you would stand behind and support its effectiveness?
Jared, not yet. The thing I dont see from all of the products Ive looked at is actual proof that they raise testosterone levels.
Hey Joe
I have a quick question about this product
Wanted to know how to use it. The thing says to take 3 capsules 2 to 3 times a day. Does that mean I have to take 9 capsules a day if I’m using this product 3 times a day.
It’s so vague since it has 90 capsules and it’s suppose to be a 30 days supplement
Zaid, that sounds like about 9 capsules to me. Id say call the company and see what they say.
I was wonder why you are so skeptical about t boosters? The reason i was wondering is that there are foods you can eat that naturally help with t levels ( almonds, dates,ect) i cant think of anymore off the top. So why couldn’t there be t boosters that work? And all the research that you say you have done do you have any recommendations???
Thank you
Sam
Sam, I’m skeptical because I have not seen any proof (study) that actually showed that a supplement actually raised testosterone. None of the websites for products Ive looked at have shown me this proof. That’s why I recommend people get their T levels tested first and then again a month later to see if a product works or not.
I usually steer clear of recommending things. That’s what others do. I usually prefer for people to make choices based on the evidence. That said, when it comes to testosterone booster supplements, until I see peer reviewed proof that a product works, I remain very skeptical of all of them.
Hi,
I am a new fan, I am thinking of taking progene because the ad is believable, what can you say?
Ramon
Ramon, its on my list to review. If you know the ingredients, look them up with the search box and see if Ive mentioned them already
I am 48 and tried synteroid for three months, but I didn’t see any positive improvements.
Hello folks. I have a horrible metabolism which makes it hard for me to keep a “lean figure” so I’m constantly looking for something to give me an edge. I work out daily and eat as healthy as humanly possible over here in Afghanistan. (The food variety and quality is questionable to say the least)
I do use supplements in the gym, I’ve had the best results with BSN products such as Nitrix, N.O. Xplode, and Syntha 6. Though I was making noticeable strength and mass gains, I have always longed for the “chiseled” look.
I started stacking Syntheroid with my BSN products and after two cycles, I could honestly say that I was the most defined I’d ever been. Whether it boosted my testosterone levels or not, I never had tests done so I have no proof or even a belief that it did that, but I did have very noticeable differences in my muscle tone. Not every supplement works for every person, but I got the effects that I was looking for in this product.
Can you actually answer Brian’s question or do you not know?
Jud, Sorry if I was vague. It was not my intention. I think I gave Brian a better answer than “what product works” because so few men get their T levels checked first. They assume (because TV ads etc make us believe it) that lack of energy, sex drive etc is due to lack of testosterone. Thats not always the case. Humans are just more complicated than that. For example, lack of erection ability can be a sign of heart disease.
Testosterone boosters do not make sense to me because if any of them did work (none that Ive seen show me proof they do work) the body would decrease its natural T production.
I admit that T booster supplements are not an area I spend a lot of time researching because most of them contain the same things – like tribulus – which lack good proof and as Ive said, the idea of them just makes no sense to me from a hormone standpoint.
I think by getting T levels tested first, men will know if their levels are indeed low – and if its they aren’t , it will hopefully get men speak to their doctor about whats troubling them, and see if they together can get to the real reason for their symptoms.
joe,, what is considerd low testosterone at age 50 my test came back 288 total testosterone isnt that low for my age,????
Phil, thats a good question and Im not sure what normal T levels are for a man who is 50. What did your doctor say? I’d ask him/her or your pharmacist. Pharmacists are VERY educated in biochemistry endocrinology etc and I feel are under used by people.
I have been taking it for 5 days now in all honesty on day 2 I found i was constantly getting an erection but as far as being stronger or having more energy thats a big negatory gentleman
THIS PRODUCT MADE MY BROTHER’S CHEST/STOMACH HAVE SEVERE HEART BURN , INDIGESTION, THREE DAYS WOULD APPRECIATE IF ANYONE ELSE IS HAVING THIS PROBLEM
what testostrone booster would you recommend to someone 45 lifting weights ..
Brian I recommend before you try anything, you get your testosterone checked by your doctor. this will give you a baseline number to check to see if ant product works – and to see if you really are low in testosterone. the test is probably covered by insurance but even if its not, the test is less than $100.