Best Supplements For Weight Loss and Muscle Gain

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This article discusses ten popular dietary supplements that are designed to assist you losing weight or building muscle. But do they work or is that just marketing smoke?

We’ll be looking at their peer-reviewed clinical results to see how effective (or not) each of these products really is.

Table of Contents show

What are (supposedly) among the best supplements for weight loss and muscle gain on the market these days?


Top 5 Muscle Gain Supplements

  1. Protein supplements
  2. Creatine
  3. Essential amino acids
  4. HMB (beta-hydroxy beta-methylbutyrate)
  5. Branched-chain amino acids

Top 5 Weight Loss Supplements 

  1. Caffeine
  2. Green tea extract
  3. Protein powder
  4. Glucomannan
  5. CLA (conjugated linoleic acid)

The International Society of Sports Nutrition (ISSN) has classified the above muscle gain and weight loss supplements as either apparently effective or possibly effective for their respective purposes.

Read on to see which ones make the grade & which of these have no sports science proof for providing any benefit.


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Science resources included

As is my custom here on heydayDo, I will provide links to all of the relevant sports science & medical resources, clinical studies, and nutritional data used in this article.


Muscle gain or weight loss supplements only

IMPORTANT NOTE: This article focuses just on muscle gain & weight loss supplements. 

Therefore, it excludes a few things that are proven to be effective as exercise performance-enhancing supplements, but not as muscle builders in the strictest biological** sense.


** – Exercise performance enhancers help you while you’re working out to gain muscle, but they’re not part of the metabolic process that grows your muscles like protein & creatine are, for example.

So I left the performance enhancers out of this article.

These include beta-alanine and citrulline malate among others, both with some sports science evidence showing they may boost your strength training workout results.

If you’d like to read about the performance-enhancing benefits they can bring to your muscle gain program, you can read about them here on heydayDo in an article I wrote: Does Pre-Workout Work? With these 7 Ingredients It Can.


Brief note on the ISSN

If you’re unfamiliar with the International Society of Sports Nutrition…

“The ISSN is the world’s leader in providing science-based sports nutrition and supplement information.” (1)

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Top 5 supplements for muscle gain

1. Protein supplements

Classified as having Strong Evidence of Effectiveness for muscle building by the ISSN

Protein is an important part of our body’s process of repairing & building muscle after strenuous exercise like weightlifting, bodyweight calisthenics, & explosive plyometrics (2).

These types of exercises have the ability to trigger muscle building by boosting our body’s protein balance somewhat.

But it’s not enough to prevent protein breakdown if you don’t consume enough protein as well.

ON Gold Standard Protein Powder

Maintaining positive protein balance

It’s important to make sure your body maintains that positive protein balance, where muscle protein synthesis is greater than muscle protein breakdown (3).

Furthermore, research has shown that following strength training, the protein metabolism period lasts about a day or so (4).

Thus for someone who works out regularly, their daily protein requirement must be met.


It’s hard for some people to eat enough protein

Sports science experts agree that someone who’s regularly exercising needs more protein than the typical inactive person, to the tune of 0.7 – 1 gram per lb. of bodyweight per day (5).

While it’s certainly possible that an athlete or someone who strength trains regularly could get all the daily protein they need from food, “it don’t come easy”, as the old song goes.

Work schedules, lack of easy access to high-quality lean protein, and the sheer volume of solid food necessary to hit their daily protein number make it difficult for some people to do so.

Enter protein supplements.

Muscle Feast Protein Powder

Protein supplements make it easy

Protein supplements, especially protein powder, make getting your daily requirement of quality protein a breeze.

They’re convenient & easy to travel with, and whey is very easy to mix with any liquid.


Do protein supplements really work?

Sports science has clearly proven that high quality protein (& particularly the fast-digesting kind like protein powder) is very effective at providing the right nutrients to stimulate muscle growth (6).

A meta-review of over 20 sports science research studies on protein supplementation concluded that

“Protein supplementation increases muscle mass and strength gains during prolonged resistance-type exercise training in both younger and older subjects” (7).


Strong evidence of protein’s effectiveness

The ISSN is one of the world’s leading authorities on dietary supplements designed for athletic performance, and in their Position Stand on Protein & Exercise they state that

“many published investigations report that protein supplementation results in significant improvements in lean body weight” (9).

They list protein as one of only 4 supplements that have “Strong Evidence to Support Efficacy” in the category of Muscle Building (10).


2. Creatine

Classified as having Strong Evidence of Effectiveness for muscle building by the ISSN

Creatine, and in particular, creatine monohydrate, has been heavily studied in both sports science & medical research for decades (11).

It has been consistently proven to build muscle and to improve our strength as well (12).

Creatine builds muscle by increasing your ability to intensely exercise, which with strength training means you’re doing more reps, more sets, & lifting more weight…and that leads to more muscle growth.

More muscle growth leads to more strength, and round & round your muscle-building process continues (13).

Optimum Nutrition Creatine Monohydrate

Does creatine really work?

Well, the ISSN certainly says it does:

“Creatine monohydrate is the most effective ergogenic nutritional supplement currently available to athletes with the intent of increasing high-intensity exercise capacity and lean body mass during training.” (14)


3. Essential amino acids

Classified as having Strong Evidence of Effectiveness for muscle building by the ISSN

In addition to protein, creatine monohydrate, & HMB (discussed below), essential amino acids (EAAs) are the only other exercise supplement on the planet in ISSN’s Strong Evidence of Effectiveness category (15).

We’ve seen that protein is effective at building muscle, and it’s a fact that amino acids are the building blocks of protein (16).


EAAs stimulate MPS

So perhaps it’s no surprise to find out that essential amino acid supplementation has been proven many times over to generate MPS – muscle protein synthesis – just like protein (17).

In fact, it is the abundance of EAAs in quality protein sources that make protein so effective at muscle building (18).

Pure Encapsulations Essential Amino Acids capsules

EAAs are good if you don’t like protein powder

Essential amino acid supplementation makes sense for someone who can’t get enough dietary protein from food and who’d prefer an alternative to protein powder.

Bear in mind you’ll have to swallow a lot of capsules to equal the amount of essential amino acids that come in every scoop of well-made protein powder.


Top protein powders have plenty of EAAs

There’s no reason to take EAAs if you’re supplementing your daily protein intake with a high-quality protein powder, since the best ones are packed with plenty of  essential amino acids in them already.


4. HMB

Classified as having Strong Evidence of Effectiveness for muscle building by the ISSN

Beta-hydroxy beta-methylbutyrate (which thankfully is also called simply HMB) isn’t as well known as creatine, but it too has been studied in sports science for decades like creatine has.

In fact, a large scientific review of hundreds of fitness supplements looked at research studies going all the way back to 1967.

Out of over 250 supposed exercise performance-enhancing supplements only 2 were proven to be effective.

One was of course creatine, and the other was HMB (19).

Bulk Supplements HMB Powder


What is HMB?

If you’re unfamiliar with HMB, you might recognize where it comes from, the branched-chain (& essential) amino acid leucine.

HMB is one of the things produced when our bodies break down leucine that we consume (20).


Provides other exercise benefits too

In this article we’re only interested in what HMB’s ability to build muscle is, but it’s worth mentioning that it has other exercise performance benefits that have been verified by sports science (21). HMB can:

    • increase strength & power in resistance training
    • help recovery by reducing exercise muscle damage
    • increase muscle mass in elderly & sedentary people
    • increase fat loss during regular exercise

Does HMB really work for gaining muscle?

While the ISSN and all of the sports science research behind it give HMB the two thumbs up for its ability to build muscle, there is a definite catch:

HMB studies have shown that it only works really well for beginners who are new to strength training. 

Untrained people just starting out experience nice gains in muscle mass and strength increases in their first several weeks of training while supplementing with HMB (22).


HMB results are not as impressive for advanced lifters

But a number of studies using HMB & collegiate athletes & other experienced weight trainees have mixed results as far as significant muscle building effectiveness goes, as you can see from the table here on this link (23).


5. Branched-chain amino acids

Classified as having Limited or Mixed Evidence of Effectiveness for muscle building by the ISSN

The three branched-chain amino acids are leucine, isoleucine, & valine.

Branched-chain amino acids (BCAAs) are another popular supplement used in fitness training, even though you can get enough of them just by including a good amount of high-quality protein in your diet.

People who are vegan may not get enough of these BCAAs in their diet however, since the BCAAs come mostly from animal, fish, & dairy sources.

BCAAs have been shown to be effective at:

      • reducing muscle soreness (24)
      • reducing muscle damage from exercise (25)
      • improving muscle recovery (26)

ON BCAA Capsules


Do BCAAs really work at building muscle?

BCAAs are amino acids and as I mentioned earlier, amino acids are the building blocks of protein (27).

So it seems reasonable to think that since protein builds muscle, maybe BCAAs would too.

But the results just aren’t there.

Which is kind of surprising, given how BCAAs are huge sellers in the supplement business.

The ISSN notes that the clinical study results are too mixed to anoint BCAAs as definitely effective for muscle gains (28).

There are several studies like this one here, where the group taking BCAAs before & after weightlifting (for 8 weeks) had no strength or muscle growth advantage over the placebo group (29).

Again, BCAAs have been proven effective at muscle recovery, but as far as muscle building? Not so much.

Shop BCAAs online

If you’re interested in pure BCAAs, I’ve researched the product category thoroughly and shared my findings here on heydayDo in this article, Best BCAAs without Artificial Sweeteners.

And if you’d like more sports science evidence panning BCAAs’ ability to build muscle, I gathered some of it in this blog post Hype Check: Are BCAAs Worth It, Or Just Buzz Without The Bang?



Top 5 supplements for weight loss

1. Caffeine

Classified as effective & generally safe for weight loss by the ISSN

Besides the ISSN, the National Institute of Health also recognizes caffeine for its thermogenic effect that increases fat burning (30).

Caffeine’s another supplement that has had a ton of medical & scientific research conducted on its effects & benefits, so its ability to boost your metabolism & burn fat is well-known (31).

Studies have shown that caffeine can boost your resting metabolic rate* by over 10% when consumed throughout the day, and by 3-4% over the couple of hours following a single 100mg dose – which is equivalent to a regular cup of coffee (32).

* – Your resting metabolic rate is how many calories your body burns when you’re…you guessed it, at rest.

Caffeine anhydrous (the dried powder version caffeine supplements typically come in) is a very common ingredient in pre-workout supplements, and can be purchased a la carte as well:

Bulk Supplements Caffeine

Caffeine curbed appetites in overweight people

Another study found that drinking coffee during breakfast reduced the amount of food eaten later in the day by overweight people, compared to those who drank water (33).


green tea farm aerial view, with worker in rows of tea plants

2. Green tea extract / green tea

Classified as Possibly Effective for weight loss by the ISSN

Green tea & green tea extract have been one of the best-selling non-vitamin/non-mineral supplements over the past couple of decades, thanks to their reported weight loss benefits (34).

As usual, let’s look under the hood before driving off into the sunset with a bottle of green tea pills in hand.


Catechins & caffeine

By the way, catechins is the name given to the flavonoids & antioxidants found in green tea plants, and they’re (besides the caffeine) the main ingredient in terms of weight loss potential (35).

Also, if you’re reading any green tea product info you may see the manufacturer mention EGCG.

This is the catechin that is most associated with green tea’s ability to create weight loss (36).


The NIH says the research is legit

NIH’s Office of Dietary Supplements (ODS) examined the research studies on the active ingredient in green tea & green tea extract & found

several clinical trials of good methodological quality on green tea catechins with and without caffeine”. (37)

This is important, especially so when talking about a weight loss supplement.

There is so much B.S. thrown at us by sketchy supplement manufacturers, including products with self-funded “research studies” of very questionable quality.


But does green tea extract really work?

The ODS takes a real dim view on supplements sold with weight loss claims.

So when they say that green tea/green tea extract demonstrates a “modest effect on body weight”, take it as a compliment, albeit a measured one.


Bottom line according to the NIH:

Their verdict is that the research is trustworthy, but the results are mixed.

This means that some studies show significant weight loss benefits, others do not.


ISSN concurs and says it might work

The ISSN has the same opinion as the NIH. Some legitimate studies showed significant weight loss results, some did not (38).

For example, when combined with a low-calorie diet, green tea extract caused significantly greater weight loss compared to the low-cal diet alone (39).

And here, researchers found that green tea catechins combined with exercise reduced belly fat more than exercise alone (40).

However, the ISSN also says that other studies 

“have not supported these findings and have reported that supplementation of these extracts does not affect weight loss”.


Bottom line per the ISSN:

Green tea extract has shown itself to be effective at fat-burning & subsequent weight loss in some cases, but ineffective in others.

Catechins with the tea’s caffeine appears to be more effective than catechins alone.

Shop green tea extract online


3. Protein powder

Protein powder is good for more than building muscle, it turns out. Numerous nutrition science studies have shown that high-quality lean protein is an effective weight loss tool.


Higher lean protein = more weight loss

A large review of 20 years’ worth of weight loss studies found that lean high-protein diets were much more successful at creating:

      • greater weight loss
      • greater fat mass loss
      • better boost in metabolism
      • better preservation of lean muscle

compared to other diets with lower protein in them (41).


Protein curbs hunger pangs

Other studies have found that protein is better than the other macronutrients – fats & carbohydrates – at providing satiety, i.e., the “I’m not hungry” feeling (42).

Researchers believe this is due to protein’s ability to do a better job of mellowing out the brain hormones that send out hunger signals (43).


Protein helps avoid metabolism slowing

When people are on a weight loss program, their body can adjust to the lowering weight by slowing down their metabolism.

That’s no good, since as the metabolism slows, regaining the weight becomes more likely (44).

However, a cool thing about protein supplementing during weight loss is that maintaining a high protein intake can prevent that metabolic slowdown (45).


The best protein powders are low in calories

Protein powders are ideal for this since the best ones are very low in calories. And the ISSN classifies low-calorie foods like:

      • protein supplements
      • meal replacement products (MRPs)
      • ready-to-drink supplements (RTDs)

as effective & generally safe to use” (46).

For example, the whey isolate that I drink delivers 21.5 grams of protein in only 89 calories, and has only 0.2 grams of fat in it and 0.2 grams of carbs.

For reference, 22 grams of protein from either eggs (47) or from 85% lean ground beef (48) are both just under 300 calories.


Konjac plant that glucomannan is made from

Is this thing going to help anybody lose weight?


4. Glucomannan / dietary fiber

Classified as Possibly Effective for weight loss by the ISSN

As the ISSN says,
One of the oldest and most common methods of suppressing the appetite is to consume a diet that is high in fiber.” (49)


Glucomannan is the latest high-fiber supplement to become popular for its weight loss potential in recent years.

It comes from the root of the konjac plant which is native to China & southeast Asia (50), and that’s a picture of it above.

Note that in those cultures that have eaten & used the konjac plant medicinally for centuries, it’s not used for weight loss purposes.

It’s not a fat-burning chemical like caffeine or the catechins found in green tea.

Glucomannan’s mechanism of action is to make you feel so full that you don’t want to eat: it can absorb 50 times its own weight in water (51).


Does glucommannan really work?

Important to note: While the ISSN lists glucomannan as an example of high-fiber supplements that are possibly effective, they’re actually speaking broadly about the potential benefits of a well-rounded, high-fiber diet (52).

And not about glucomannan specifically, as far as I can tell.


The NIH says results are mixed

In their report on glucomannan, their Office of Dietary Supplements listed 8 studies for reference.


One study showed weight loss

One study demonstrated some weight loss from glucomannan supplementation.

Over an 8 week period 20 obese women were given glucomannan prior to each meal, and after 2 months, they’d lost 5.5 lb. on average** (53).


** – Random sidebar: I don’t think those results are impressive at all, considering this is a supplement that you’ll have to pay for.

Heck, I lost 19 lb. in 3 months last year with no weight loss pills, as part of an experiment I did on myself combining HIIT & a low-carb diet.

I plan to write an article about that but until I do, contact me if you want any diet & workout details.)


Seven studies found no effectiveness

The rest of the research studies that the ODS mention all failed to report any meaningful weight loss (54).


Bottom line on glucomannan for weight loss:

Glucomannan probably isn’t worth spending money on.

The ISSN’s idea of eating a high-fiber diet is a good one, and you can do that by simply making smart food choices at the grocery store.

There’s no need to pay extra for a fiber supplement.


Two Final Notes:

* Some glucomannan products are permanently banned in Australia over health concerns (55).

* Glucomannan does have a history of unwanted side effects (56). And it also has interactions with certain drugs, including anti-diabetes medications (57).

Shop glucomannan online


5. CLA (conjugated linoleic acid)

Classified as Possibly Effective for weight loss by the ISSN

Another extremely popular supplement touted for its weight loss benefits is conjugated linoleic acid, or CLA for short.

In food sources we eat, the CLA comes from dairy & meat. (58)

But the supplement on the market is made synthetically by changing the chemical structure in vegetable oils.


Does CLA really work?

The ISSN has listed CLA as possibly effective for weight loss.

As with a couple of other weight loss supplements we’ve looked at in this article, CLA’s research study results are a mixed bag.


A few CLA studies showed some weight loss

The ISSN notes a few studies like this one, where CLA reduced the body fat mass in obese people over an 8-week period (60).

And here, a year-long study also showed CLA reducing body fat in overweight subjects by 7-9% compared to the placebo group (61).


And a few CLA studies didn’t

For example, a meta-review of 7 CLA research clinical trials that all lasted between 6 & 12 months determined that the net weight loss over all the studies was only a little over 1 lb. (62).

And here, an 8-week study combining aerobic exercise, CLA, & obese young women determined that

“CLA supplementation associated with aerobic exercise has no effect on body fat reduction” (63).


These inconsistent results led the ISSN to conclude:

“human studies, at best, suggest a modest ability…of CLA to stimulate fat loss” (64).


The NIH says basically the same thing

“Although CLA appears to reduce body fat mass in animals, results from human studies suggest that its effects are small and of questionable clinical relevance” (65).


Bottom line: Considering its best-selling popularity, the actual scientific results for CLA are not very impressive.

Shop CLA online



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In review…

Best muscle gain supplements

      • Creatine
      • Protein supplements
      • Essential amino acids (EAAs)
      • HMB (for inexperienced strength trainees only)


Best weight loss supplements

      • Caffeine
      • Low-calorie foods, like:
        • protein powder
        • meal replacement products
        • ready-to-drink supplements


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Weight loss supplement FAQ

Here are answers to a couple more of the commonly asked questions regarding weight loss supplements.


What supplements burn fat and build muscle?

From research study evidence compiled at the NIH’s Library of Medicine, protein appears to be the only supplement capable of both burning fat & building muscle.

Research shows:

      • Protein has the ability to burn fat due to its thermogenic effect (66)
      • Protein has the ability to trigger muscle growth by stimulating muscle protein synthesis. (67)


Does CLA increase muscle mass?

According to the International Society of Sports Nutrition,

“…there is little evidence that CLA supplementation during training can affect lean tissue accretion and has limited efficacy” (68).


lean tissue accretion –  an increase in muscle mass

limited efficacy – limited effectiveness

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Wrapping Up

Related fitness supplement articles here on heydayDo

Natural & Supplemental Alternatives to Creatine

Protein Powders Without Artificial Sweeteners

BCAAs Without Artificial Sweeteners

I hope that my article on the best supplements for muscle gain & weight loss is useful to you, and I wish you well on your fitness journey.

– greg

About The Author

heydayDo author Greg Simon

Hi, I’m Greg Simon. Fitness training & nutrition researching since 1982. ISSN (International Society of Sports Nutrition) Pro Member. MBA, B.Sc.

Author. Surfer. Organic food grower. Congenital heart disease survivor (so far). is my wellness blog that’s about encouraging a healthy lifestyle as we age. 

I share my fitness training experience as well as the sports science research I’ve done on the many benefits strength building, exercise, & good eating habits offer us. 

I also write review articles after product testing and evaluating home gym equipment & fitness supplements.

My hope is that you’ll find useful or encouraging information here on my website that will benefit your unique fitness journey.

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