A Complete Supplement Guide to AAKG
Your buddy at the gym has been talking about the AAKG supplement for a while now. And, yeah, he’s looking pretty strong. But should you take AAKG—short for arginine alpha-ketoglutarate, and sometimes referred to as arginine—as part of your muscle-building supplement routine?
“AAKG has become more popular among weightlifters and other athletes lately, thanks to reports that it can enhance muscle strength and recovery,” says Kim Yawitz, RD, CrossFit Level 1 Trainer, and owner of Two Six Fitness in St. Louis, MO.
Even if you’re training consistently and eating muscle-building foods, building muscle can be challenging, she says, and “the supplements industry is very good at convincing people they’re just one more pill or powder away from the body of their dreams.”
Still, many people add supplements like AAKG to their routines to get more dramatic results in less time and with less effort, Yawitz says. If you’re curious if you should buy into the AAKG supplement hype or not, keep reading to learn more about what is AAKG, its potential benefits, and what you should know before adding AAKG to your cart.
What Is Arginine Alpha-Ketoglutarate (AAKG)?
AAKG is a non-essential amino acid that’s necessary when it comes to making nitric oxide in the liver. “Both AAKG and nitric oxide amplify the beneficial muscle-building effects of exercising and nutritional supplements,” explains registered dietitian and American Dietetic Association spokesperson Jim White.
And a little science terminology 101 for the curious: “All amino acids have two different configurations—a D configuration and an L configuration,” says Yawitz. “The L-form is the only one that’s active in the body. In the context of supplements, arginine and L-arginine are the same thing.”
Is AAKG the Same Thing as L-Arginine and Arginine?
The AAKG supplement is made by combining L-arginine (arginine, for short) with a substance called alpha-ketoglutarate, says Yawitz. It goes without saying, but talk with your doctor or registered dietitian before adding another supplement to your routine.
So, how does AAKG play into the fitness scene?
“Like all amino acids, L-arginine is used to make proteins in the body, but arginine also has a few unique properties that make it appealing to weightlifters and other athletes,” says Yawitz.
AAKG Benefits
Caveat alert: While many studies have examined AAKG benefits, the findings are not clinically replicated time and time again. Take the proposed AAKG benefits with a grain of salt.
1. Potential to Boost Blood Flow
“AAKG is best known for helping the body make more nitric oxide—a substance that helps widen blood vessels,” Yawitz says. This increases blood flow without raising blood pressure. In theory, it allows more nutrients to reach muscles and more quickly removes metabolic waste products during exercise.
In short: By having more blood reaching muscles and tissues, it circulates a larger amount of carbohydrates, proteins, and various muscle-building hormones.
2. Potential to Boost Muscle Growth and Strength
AAKG has garnered interest from the bodybuilding community, as it's believed to increase your pump. That may be because, “in addition to helping the body create more cellular energy, there’s some evidence that alpha-ketoglutarate can help prevent muscle protein breakdown during exercise,” says Yawitz. She notes that combining arginine and alpha-ketoglutarate is reported to help the muscles work harder and recover faster, leading to increased muscle growth over time.
“Evidence also shows that L-arginine stimulates protein synthesis, which helps the body build muscles, increasing their size, strength and endurance,” echoes White.
While these small studies suggest AAKG supplements increase strength, power, and motivation to exercise in young athletes, in other studies, AAKG was no better than a placebo, Yawitz says. In one study, it wasn't as good as caffeine in tests of upper body strength,” she adds.
3. Potential to Boost Insulin
Among AAKG benefits, arginine can help the body create more insulin, increasing the amount of glucose and amino acids available to muscles for tissue growth, Yawitz says. It's been found that, by taking 10 to 15 grams of AAKG per day, the body’s insulin level increases by 20 to 30 percent, which, in turn, theoretically increases strength gains and muscle growth.
4. Potential to Boost Muscle Pump
“Several studies found that the use of arginine alpha-ketoglutarate by bodybuilders promoted larger and longer lasting pumps,” White says. “The muscles were tighter and stronger. Some of the bodybuilders reported feeling ‘pumped’ all day long.”
Other areas of inquiry include the link between AAKG and increased tolerance for high-intensity exercise and higher capacity for aerobic and anaerobic exercise, says Yawitz, stressing that “there’s not a lot of compelling evidence that AAKG gives athletes any performance advantage.”
The bottom line is it’s difficult to draw conclusions whether AAKG is beneficial as a sports supplement simply because studies on it are few and far between, says Yawitz, further commenting that most available studies are very small, and several are also looking at multi-ingredient supplements with AAKG and other performance-enhancing substances.
One more thing, in case you’ve heard the rumors floating around that arginine may thicken hair. Yawitz shares there’s some evidence that arginine can help with hair growth, but this is for people with alopecia or telogen effluvium (a type of temporary hair loss brought on by a life stressor or surgery). In this case, enhanced hair growth is usually seen with topical preparations instead of oral supplements.
AAKG Side Effects
Are there any risks in taking AAKG supplements? So far, research is inconclusive on the adverse side effects of this product and it appears to be safe for most adults. In one eight-week study, subjects reported no abnormal side effects from taking about 4 grams per day of AAKG.
However, a 2009 paper reported three patients who were admitted to the emergency room with very negative effects including dizziness, vomiting and loss of consciousness. AAKG is not recommended for continuous, high-level use for more than 60 days.
AAKG is a natural blood thinner so people taking blood thinners should use caution. Some doctors believe that people with any form of the herpes virus (cold sores or genital herpes) should not consume AAKG as it may induce virus symptoms.
AAKG Dosage
In terms of dosage, Yawitz says AAKG hasn’t been studied enough to know how much is safe. “In a small 2006 study, doses of 12 grams daily appeared safe and well-tolerated among healthy male subjects. Those who don’t tolerate it as well most commonly experience headache or gastrointestinal side effects—like nausea, bloating, and diarrhea,” she says. Also, there have been a few reports of serious side effects and hospitalizations among healthy young men taking AAKG supplements in doses as small as 6 grams daily, cautions Yawitz.
Given the scarcity of studies on AAKG, there’s no universal standard for how much AAKG men should take, how often they should take it, and how long they should use it, says Yawitz who “wouldn’t recommend it to my clients without significantly more evidence that it’s safe and effective.”
“For those who’d still like to try it, I’d suggest starting at a very low dose of 2 to 3 grams and increasing by 2 to 3 grams every few days as tolerated, with a maximum dose of 12 grams daily,” she says. If you start noticing any side effects, consult with a trusted healthcare professional.
How to Use AAKG
There are three main ways to take AAKG, and which route to go with is a personal preference. “AAKG is available in capsule and powder form and in some multi-ingredient sports supplements (like pre-workout drinks),” says Yawitz. “It’s best to start slow and follow the instructions on the label.”
You may also be wondering how long you should take AAKG and if it’s okay to take it for the foreseeable future (read: months, years, and decades ahead). Yawitz says, as with the dosage amount, there’s not enough evidence to know if it’s safe to use AAKG for extended periods because there haven’t been any long-term human studies.
“There’s some evidence that long-term arginine supplementation could increase the risk of kidney damage, at least in rodents,” says Yawitz. “According to the National Institutes for Health, using up to 9 grams of arginine daily is likely safe for healthy adults, at least in the short term.”
So, can you use AAKG every day? Based on NIH safety guidelines, Yawitz says it’s best to use AAKG daily for only a couple of months (for example, during a single eight- to 10-week training cycle).
AAKG Drug Interactions
Like any supplement, there are potential interactions with medications. “Some studies have shown that arginine can lower blood pressure, so it’s best not to take it with any medication that has a similar effect (including antihypertensives, nitrates, and Viagra),” says Yawitz. “You should also avoid using AAKG supplements if you take diabetes medications and blood thinners.”
A Dietitian’s Final Take on AAKG
Yawitz thinks many people could benefit from ditching the supplements and focusing more on muscle-building basics—like lifting weights three to four times per week, eating enough calories and protein to support muscle growth, sleeping at least seven hours nightly, and scheduling regular active recovery days. Yeah, it requires hard work, but slow and steady wins the race.
“If you’re going to try supplements, I’d recommend starting with creatine and whey protein—both of which have been extensively researched and have a solid track record among adults who exercise,” she adds.
