Uses

HMB (beta hydroxy-beta-methylbutyrate) is a metabolite of the essential amino acid leucine (one of the branched-chain amino acids).

What Are Star Ratings?

This supplement has been used in connection with the following health conditions:

Used for Why
3 Stars
High Cholesterol
3 grams daily
Supplementing with HMB, or beta hydroxy-beta-methylbutyrate, is an effective way to lower total and LDL cholesterol.
The combined results of nine double-blind trials indicate that supplementing with HMB, or beta hydroxy-beta-methylbutyrate, effectively lowers total and LDL cholesterol. All trials used 3 grams per day, taken for three to eight weeks.
2 Stars
HIV and AIDS Support and Preservation of Lean Body Mass (Arginine, Glutamine)
1.5 grams of HMB, 7 grams of L-glutamine, and 7 grams of L-arginine twice per day
The combination of glutamine, arginine, and HMB may prevent loss of lean body mass in people with AIDS-associated wasting.

The combination of glutamine, arginine, and the amino acid derivative, hydroxymethylbutyrate (HMB), may prevent loss of lean body mass in people with AIDS-associated wasting. In a double-blind trial, AIDS patients who had lost 5% of their body weight in the previous three months received either placebo or a nutrient mixture containing 1.5 grams of HMB, 7 grams of L-glutamine, and 7 grams of L-arginine twice daily for eight weeks. Those supplemented with placebo gained an average of 0.37 pounds, mostly fat, but lost lean body mass. Those taking the nutrient mixture gained an average of 3 pounds, 85% of which was lean body weight.

2 Stars
Obesity
3 grams per day or 17 mg per pound of body weight per day
HMB may improve muscle growth and overall body composition when combined with an exercise program in people who are not already highly trained athletes.

Biochemical and animal research show that HMB has a role in protein synthesis and might, therefore, improve muscle growth and overall body composition when given as a supplement. However, double-blind human research suggests that HMB may only be effective when combined with an exercise program in people who are not already highly trained athletes. Double-blind trials found no effect of 3 to 6 grams per day of HMB on body weight, body fat, or overall body composition in weight-training football players or other trained athletes. However, one double-blind study found that 3 grams per day of HMB increased the amount of body fat lost by 70-year old adults who were participating in a strength-training program for the first time. A double-blind study of young men with no strength-training experience reported greater improvements in muscle mass (but not in percentage body fat) when HMB was used in the amount of 17 mg per pound of body weight per day. However, another group of men in the same study given twice as much HMB did not experience any changes in body composition.

1 Star
Athletic Performance and Improving Body Composition with Strength Training in Untrained People
3 grams daily
HMB, a breakdown product of an essential branched-chain amino acid, has a role in protein synthesis and might, therefore, improve muscle growth and overall body composition. Research suggests it might be effective only when combined with an exercise program in people who are not already highly trained athletes.
HMB (beta hydroxy-beta-methylbutyrate) is a metabolite (breakdown product) of leucine, one of the essential branched-chain amino acids.  Biochemical and animal research show that HMB has a role in protein synthesis and might, therefore, improve muscle growth and overall body composition when given as a supplement. However, double-blind human research suggests that HMB may only be effective when combined with an exercise program in people who are not already highly trained athletes. Double-blind trials found no effect of 3 to 6 grams per day of HMB on body weight, body fat, or overall body composition in weight-training football players or other trained athletes. However, one double-blind study found that 3 grams per day of HMB increased the amount of body fat lost by 70-year old adults who were participating in a strength-training program for the first time. A double-blind study of young men with no strength-training experience reported greater improvements in muscle mass (but not in percentage body fat) when HMB was used in the amount of 17 mg per pound of body weight per day. However, another group of men in the same study given twice as much HMB did not experience any changes in body composition.

How It Works

How to Use It

Most people do not need to use HMB. For those involved in regular exercise who do choose to take this supplement, the research generally uses 3 grams of HMB per day in combination with resistive exercise, such as weight lifting.

Where to Find It

Small amounts of HMB are present in many foods of animal and plant origin, especially alfalfa and catfish. The amino acid leucine is metabolized into a compound called alpha-ketoisocaproate (KIC), which is then turned into HMB by the body. Dietary supplements of HMB are also available.

Possible Deficiencies

HMB is not an essential nutrient. The body creates HMB from leucine, so any diet containing sufficient amounts of leucine (most do) should lead to the adequate production of HMB. Limited evidence indicates that athletes may benefit from supplemental intake of HMB.

Interactions

Interactions with Supplements, Foods, & Other Compounds

At the time of writing, there were no well-known supplement or food interactions with this supplement.

Interactions with Medicines

As of the last update, we found no reported interactions between this supplement and medicines. It is possible that unknown interactions exist. If you take medication, always discuss the potential risks and benefits of adding a new supplement with your doctor or pharmacist.
The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers' package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a supplement with your doctor or pharmacist.

Side Effects

Side Effects

At the time of writing, there were no well-known side effects caused by this supplement.