• Editor Rating
  • Rated 2.5 stars
FREE TRIAL to $131.67
  • 40%

  • RexGain
  • Reviewed by:
  • Published on:
  • Last modified: June 5, 2020
  • Overall
    Editor: 52%
  • Effectiveness
    Editor: 49%
  • Speed of Results
    Editor: 51%
  • Sustaining Results
    Editor: 49%
  • Safety
    Editor: 53%
  • Value
    Editor: 51%

What Is RexGain?

RexGain is a pre-workout supplement designed to streamline a collection of muscle-building ingredients into one easy-to-take formula. For many people, getting a supplement stack just right involves buying a large number of supplements. Since these supplements can often fill a pillbox quickly, it can be hard to keep up with such a complex routine. When you choose this supplement, though, you get the benefits of many workout supplements in one. RexGain is designed to help support you before, during, and after your workout. It does this by increasing blood flow to muscles.

Increasing blood flow to muscles may sound simple, but this function has positive implications for recovery and the workout itself. First, this increased blood flow involves vasodilation, or a relaxing of the blood vessels, so it does not come with an increase in blood pressure. The increase in blood flow means that the muscles receive more oxygen and important nutrients, including those in your supplements. It also means that you will not experience fatigue as quickly as usual. This supplement works to clear ammonia from your system as you exercise. Since ammonia buildup is related to fatigue, this generally means you can exercise longer with no adverse effects. Additionally, the additional oxygen delivery helps fend off fatigue, too, as lack of oxygen contributes to the buildup of lactic acid, which causes the burn you feel when you approach muscle failure.

RexGain is a supplement that has a variety of benefits, and it is easily integrated into just about any supplementation routine. It comes in easy-to-take capsules, and you have the option of having it shipped to your door every month to save time and effort. If you want to take a supplement that has the ability to enhance performance and help you reach physique goals sooner, then this is very likely a smart supplementation choice for you.



This supplement is manufactured by a company that makes only this supplement. For many, especially those who may be used to making purchases from major manufacturers that make countless supplements, this fact may be daunting. However, there are some surprising advantages to purchasing a supplement from this sort of manufacturer. To start, when a manufacturer only makes one supplement instead of many, it can invest more time and money into the making of this supplement compared to a manufacturer that makes several supplements. Another benefit to this somewhat unusual situation is the fact that, when you call a representative from this company, he or she will likely be able to give more detailed answers to your product questions. Unlike reps for large manufacturers, RexGain product reps only need to know about one product, so their knowledge base of relevant info will likely be more complete.


How RexGain Works?

This supplement, while sold as a pre-workout, actually has benefits that extend beyond this particular function. RexGain works to support your muscular recovery, to hold off fatigue, and to give you a superior muscle pump and vascularity. Unlike many pre-workouts, the recovery support of this supplement lasts all day. If you’re like most people, you take post-workout protein after every lift. Since this supplement boosts your blood flow to muscles, it increases the delivery of this supplement to muscles. Since it does this right as muscles are primed for growth, you are likely to experience faster hypertrophy. This helps you get your money’s worth out of your other supplements, too, since they are used to build muscle. However, this is not the only way in which this supplement works. One major way it can further your fitness goals is by enhancing delivery of both oxygen and nutrients to the muscle. But why is this important?

To start, we all know that oxygen fuels working muscles whether you’re doing strength training or cardio. As muscles approach failure, you usually start to feel a burn. This is die to the accumulation of lactic acid in the muscle tissue as oxygen runs out. When you have increased oxygen delivery to the muscles, this delays the burning sensation and allows you to run farther and/or lift longer. Additionally, the delivery of supplements and nutrients to working muscles is increased when blood flow is increased, and this also supports a more strenuous workout. For example, many of us have an intra-workout that contains BCAAs (branched-chain amino acids) and sometimes glutamine. Since blood flow is supported, your muscles get more of these muscle-building compounds, this helping you get the most out of your supplementation routine. In addition, one ingredient, L-citrulline, is also good at clearing ammonia buildup in muscle. This buildup, along with that of lactic acid, contributes to fatigue, so removing it supports a more rigorous workout and better results.

One benefit of RexGain that is often overlooked is that it supports a great muscle pump. This is when your muscles fill with blood and look bigger. It’s a great confidence booster and can keep you coming back to the gym for more and better workouts. Because blood flow is increased and vessels are dilated, you will look more vascular. While this doesn’t necessarily have a tangible benefit (it’s mostly aesthetic), being more vascular can be an excellent confidence booster. It is worth noting, too, that vasodilation increases blood flow but not blood pressure. This is important, since lifting causes temporary blood pressure spikes, and further increasing blood pressure can actually be dangerous. In short, this is a supplement whose main ingredients are scientifically backed, safe, and provide actual results. If you’ve spent any time supplement shopping online, you probably see supplements whose main ingredients are based only in junk science. RexGain brings you actual ingredients from actual science.


Ingredients of RexGain

This supplement has only a few ingredients, but they are high-quality and backed by research. Below is a listing of what’s in this product, as well as a bit about how each ingredient fuels your workout:

L-arginine – This ingredient is the original nitric oxide booster. In reading above, you probably noticed that this supplement works in part by increasing the delivery of blood to working muscles. It does this by encouraging the body to produce more nitric oxide, which is the chemical responsible for encouraging vasodilation. L-arginine has been used for decades to achieve this purpose, though it took some time to discover how, exactly, it increased athletic performance. It was used in the fitness community for years before a team of researchers decided to investigate it. This team conducted a study that ultimately won the 1998 Nobel Prize in Medicine. The study found what we know today: that L-arginine increases nitric oxide production in the body, and that NO production increases blood flow (and thus oxygen and nutrient delivery) to working muscles.

L-citrulline – While L-arginine may be the OG of nitric oxide boosters, more recent research suggests that L-citrulline may actually be more effective at increasing nitric oxide production. This is because multiple studies have shown that L-citrulline is slower to degrade in the body, meaning that more of it stays around to increase muscular blood flow. By including this ingredient along with L-arginine, RexGain helps make sure that you get the best possible nitric oxide production.

Advanced nutrient delivery system – This ingredient is a bit of a mystery. While the site advertising this supplement includes it in the ingredient infographic (there is no separate listing of ingredients), it does not explain anywhere what is meant by “advanced nutrient delivery system.” This may refer to L-arginine and L-citrulline, since increasing blood flow does also enhance nutrient delivery, but there’s no way to really know for sure.



There are many advantages to choosing RexGain as your pre-workout supplement. One of these is the fact that it includes both L-arginine and L-citrulline. Many supplements, and especially supplements of lower quality, bill themselves as pre-workout supplements while only including one ingredient. Combining two high-quality nitric oxide supports not only streamlines your supplementation routine, but it also helps make sure you get your desired results faster. Another advantage is how easy it is to take this supplement. While some may prefer powder mixes, this supplement is extremely easy to take, as it comes in capsule form. This is ideal if you have limited space in your gym bag, but still want to carry your pre-workout with you. It also is easy to purchase, since it comes right to your door as part of a convenient autoship program.



This supplement has yet to earn any certificates. However, as noted above, one of its main ingredients was the subject of a study that won the 1998 Nobel Prize in Medicine. While this is not a certificate given directly to RexGain, it does support the manufacturer’s claims that this is a supplement that works. One reason behind the lack of certificates for this supplement is likely the fact that the supplements market is a saturated one. Up until fairly recently, the supplement market was small, but it has steadily grown over the decades. Now, there are simply too many supplements for those awarding certificates to get to. In time, this supplement may be able to get the recognition that it deserves.



Buying online may give some people pause, as they often want to have a way to assess the supplement before committing to a full bottle. Luckily, users of RexGain are here to offer their perspectives on this supplement:

– Chaz, 33, Benton, IN:

I have real trouble committing to a given pre-workout, and I used to always get what was on sale. But I saw a friend go from decently ripped to super ripped in a short period of time, and I asked him what he was doing. Turns out the only change was using this stuff! I was intrigued. I went for the free trial and immediately felt more focused and energized, and not just in the gym, either. It’s been about three months, and I’ve noticed definite positive physique changes. I look better, and my performance in the gym has improved, as has my job performance. My life has really changed for the better.

– Steven, 21, Miami, FL:

Initially, when I started lifting with the guys, I wasn’t really supplementing with anything. But I was sore all the time and wasn’t really making any gains at all. That’s when I decided it was time to supplement shop! I didn’t really know anything, so I went with reading on the internet and asking people at the gym. One guy suggested this. I was skeptical of internet supplements, but he was jacked, so I went with it. I love this stuff! My energy is great, and I haven’t made a whole lot of gains yet, but my soreness is almost totally gone even though I’m lifting heavier, so I consider that a win. So happy I decided to take this step. I’m also a busy college student with no car, and the autoship program is a godsend.

– Jonathan, 40, San Diego, CA:

As someone comparatively older than many at my gym, I felt like I needed new ways to keep up with the Joneses. And I found one in RexGain, though it took ages to get there. Now, I’ve broken past multiple plateaus. I lift heavier than ever, and I need less rest in between my sets. It’s awesome.

– Chet, 61, Kansas City, MO:

As a gym geezer, I stand out at the gym. It might sound dumb, but I do want to prove that we old guys can look good and lift heavy. Since I consider myself to be an example, I try and supplement well. I used to just get drugstore supplements, and some of those are good, but not all of them. A few years ago, id decided my supplement routine needed an overhaul. This was one of the new ones I chose. No regrets! My pump is great, i look vascular, and most importantly, I’m confident.


Awards & Media Coverage

As noted earlier, the sheer size of the supplement market makes it so not all supplements get reviewed and evaluated in a timely manner. As such, this supplement has not won awards and hasn’t been granted much media coverage. One main ingredient was the subject of a prize-winning study, however. In time, this supplement may get more coverage, as many nitric oxide supplements sold in the way this one is will eventually get a feature in a major men’s health and fitness magazine. In short, awards and coverage take time, and it may be awhile before this one gets it.


Money-back Guarantee

The manufacturers of RexGain stand behind the product they make, and they do offer a refund policy. If your bottle has been damaged in transit, or if you simply want to return an unopened bottle, you may do so. However, in order to make sure your return is processed, you will need to obtain a return merchant authorization, or RMA. To do so, you must contact the manufacturer directly. From there, you will receive instructions for mailing back the product for a refund. The manufacturer notes that, if you mark a shipment “return to sender,” your refund will not be processed. The manufacturer also recommends that you use a delivery confirmation system to make sure your product is not lost or damaged in transit.



Shipping is fast, since the manufacturers understand that you may want to get started with your pre-workout immediately. While delivery times will vary depending and destination, the manufacturer website notes that they will ship your product within one business day of purchase. They state that, in most cases, you will get your product in three to five business days. Shipping is for a low flat rate, and after your free trial shipment (discussed in detail below), shipping cost will be rolled in with the cost of the product for your convenience. Because the company understands that schedules change, you may alter the timing of your monthly delivery by contacting customer service as needed.


Customer Support

The customer support team at RexGain is made up of dedicated fitness professionals who are knowledgeable about both this product and fitness in general. They are available through phone, e-mail, or traditional mail. If you have general question before becoming a customer, they can help, but customer service doesn’t end once you’ve made a purchase. Even if you’re already a customer and just want some additional guidance, you can contact the support team for help on how to make this product work for you. Whether you have questions on timing, dose, research behind the product, or something else, they can help.


Safe & Secure Checkout

Especially before internet security became as strong as it was today, people have always been a bit wary of online purchasing. However, the manufacturers of RexGain have taken extra precautions to ensure the security of your information. When you make an online purchase, you’ll see that the safe encryption of this site is independently verified by McAfee Secure, TrustE, and Norton Secured. If you are worried about employees seeing your info, rest assure that you information is only used to process orders. You will not be sent spam, and your information will not be shared with any other entities. Though online buying used to be fraught withs security concerns, the state-of-the-art system employed by this manufacturer keeps your information safe.


Pricing & Free Trial

Pricing of this product is slightly more expensive than similar pre-workout supplements, but for those who ain’t sure if RexGain is right for them, it may be a good idea to go with the risk-free trial program. In this program, you can get a full month’s supply for just the cost of shipping and handling. To enroll, you pay the low flat shipping rate of $3.90. This gets you a 30-day bottle. You then have 14 days from the purchase date to decide if it’s right for you. If you’d rather not keep getting this supplement, cancel before the 14 days, keep the bottle, and owe no money. If you’d like to become a customer, do nothing, and you’ll be enrolled in the autoship program. You’ll be billed $127.77 for the trial bottle, and each month you’ll be billed $127.77 plus $3.90 and have a bottle shipped right to your door.


There are many benefits to taking this as your nitric oxide booster. They include the following:

  • It includes both L-arginine and L-citrulline.
  • It comes in capsules, which are easy to take.
  • Unlike some pre-workout supplements, it contains multiple proven ingredients.


As with any supplement, this one has some cons. They are as follows:

  • The manufacturer claims the supplement has an “advanced nutrient delivery system,” but no details are provided.
  • Some users may prefer a powdered supplement.
  • The autoship program may not be ideal for some.


Summary: RexGain is a pre-workout supplement that enhances performance and results through stimulating nitric oxide production. Nitric oxide is a chemical responsible for increasing blood flow to working muscles. This means that those muscles get more oxygen and nutrients, thus enabling you to work out harder for longer periods of time. This is a good thing for both strength and cardio training, and it also has positive implications for muscle recovery. This is because increased blood flow also means increased and improved delivery of supplements to the muscles, so your post-workout protein and other supplements are put to use. This supplement also can help you fend off fatigue, as it works to clear ammonia buildup in muscle tissue. Lastly, because increased blood flow means a better muscle pump and improved vascularity, you’ll look more ripped inside and outside of the gym.

FREE TRIAL to $131.67
RatingRated 2.5 stars

Allen Hicks is a professional bodybuilding coach and author. By using his experience, knowledge and understanding of all the intricacies regarding the fitness and bodybuilding industry, this websites delivers detailed reviews for every new supplement on the market. As an author, he may receive some small compensation for some of them, however we guarantee the neutrality regarding the evaluating of each of the products and the factuality of the information.