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The 9 Best Supplements For Hardgainers To Build Muscle & Add Size

By: Zack Mathews, NASM - CPT, CES, & PES, PN-L1

best supplements for hardgainers

The best supplements for hardgainers will be for those skinny guys and girls out there that need an extra boost to support their health and fitness goals.  Despite a consistent training program and well balanced diet, they can’t seem to move the needle.

Does that sound like you?  

It was definitely me! I was always the skinny guy growing up and remember researching hardgainer supplements.

Today I am going to provide you with the 9 best supplements for hardgainers that have helped me and my clients reach our goals.  They include:

  1. Protein Powder
  2. Weight Gainer
  3. Creatine
  4. Preworkout / Caffeine
  5. Multivitamin
  6. Fish Oil
  7. Magnesium
  8. Vitamin D
  9. Greens Powder

The 4 Best Supplements For Hardgainers To Add Size And Have Better Workouts


Protein Powder


Protein is essential for building and repairing muscle tissue but unfortunately, many hardgainers struggle to consume enough protein through their diet alone.

Protein powders are a convenient and cost-effective way to increase protein intake, with a variety of options available including whey, casein, soy, and pea/vegain protein.

Whey protein is a popular choice for its high biological value, meaning it is easily absorbed and utilized by the body.

If you’re somebody who doesn’t respond well to dairy, be aware that some whey protein has dairy so you’ll need to find one without it or get a vegan protein blend.

There are lots of different options out there so my advice on this is to keep it simple.  The less ingredients the better.

Pair adequate protein consumption with a Hardgainer Workout and you'll be on your way to packing on size and muscle!

protein powder supplement for hardgainers

Weight Gainer


For those who struggle to consume enough calories to support muscle growth, a weight gainer supplement can help. 

These supplements typically contain a combination of protein, carbohydrates, and fats to increase overall calorie intake. Hardgainers may benefit from a weight gainer supplement post-workout to replenish glycogen stores and support muscle recovery.

Are weight gainers my favorite?

Definitely not.

Actually, I would prefer you make your own homemade weight gainer shake since the ingredients will be much better.  Your stomach will thank me later. 

Learn more about if you should drink weight gainer before after your workout.

For a delicious homemade mass gainer shake, check out the recipe in the article, How To Consume More Calories In A Hardgainer Diet



Creatine is a naturally occurring substance found in muscle cells, and supplementing with creatine has been shown to increase muscle strength and size. 

It works by providing extra energy to the muscles during high-intensity exercise, allowing for increased performance and muscle growth. 

For example, let’s say you can do 10 reps of squats at 135.  Having that extra boost of energy from creatine may help you get that extra 1 or 2 reps.   Those extra reps can add up over time!

Creatine monohydrate is the most studied and effective form of creatine so make sure to stick with one of those.

Preworkout / Caffeine


Just like creatine can provide increased performance during your workout, that’s what a preworkout will do for you.

The extra energy during a workout can increase performance that can lead to more strength and muscle gains.

Since most preworkouts are loaded with caffeine, you can get the same affect with a cup of coffee or tea, to a certain level.

A cup of coffee or tea has between 50 - 100mg of caffeine while some preworkouts may have up to 400!

Make sure you respond well to caffeine if you decide to use one of these.  If it makes you feel jittery or “off” I would not recommend using it.

5 Hardgainer Supplements To Improve Overall Health


hardgainer supplement



Hardgainers may struggle to consume all the essential vitamins and minerals they need through their diet alone. Well I shouldn’t even say hardgainers, most people struggle!

A high-quality multivitamin can help fill in any nutrient gaps and support overall health and well-being. 

See what I said there?  Fill in the gaps.  You still need to eat a well balanced diet and not rely on a multivitamin for everything.

Fish Oil


Fish oil is an amazing source of omega-3 fatty acids, which have been shown to reduce inflammation, improve heart health, and support brain function. 

For hardgainers, fish oil can also support muscle growth by increasing insulin sensitivity and improving nutrient delivery to the muscles. 

Look for a fish oil supplement that contains at least 1,000 mg of EPA and DHA per serving.

You also want to make sure you have a high quality fish oil because cheap ones can have traces of metal in them.

Plus you don’t want the fish burps!



Magnesium is an essential mineral that plays a role in over 300 biochemical reactions in the body, including muscle function and protein synthesis. 

Hardgainers may be at risk for magnesium deficiency, which can impair muscle growth and recovery. Supplementing with magnesium can help ensure adequate intake and support muscle health.

In addition, low levels of magnesium may affect your ability to absorb vitamin D.  It’s important to talk to your doctors about your magnesium and vitamin D levels.

Vitamin D


Vitamin D is important for bone health, immune function, and muscle function. Hardgainers may be at risk for vitamin D deficiency, especially if they live in northern latitudes with limited sunlight exposure. 

Supplementing with vitamin D can help support overall health and may also support muscle growth and recovery.

Also, go get daily sun to increase these levels!

Greens Powder


Similar to how a multivitamin can fill in the gaps of your diet, that’s what a greens powder can do.

You should always focus on eating plenty of fruits and vegetables daily, but that still may not be enough.

Taking a greens powder will help you get the extra vitamins and minerals that your body is craving.

Disclaimer About Supplements For Hardgainers


This is important and it’s probably something you’ve realized from reading the list above.

These hardgainer supplements should not be used as a replacement for a healthy diet and consistent exercise routine. Instead, they should be used as a supplement to support your overall health and fitness goals.


If you have take all these hardgainer supplements but your workouts are lousy and you eat junk, you’re not going to see results.

Exercise and nutrition make up the biggest piece of the pie.  Even the best supplements for hardgainers still only make up a small slice.


When choosing supplements, it's important to look for high-quality, reputable brands and to follow recommended dosages.  I am not a registered dietician so I would recommend speaking with your doctor before taking any of these.

The 9 Best Supplements For Hardgainers Recap


To wrap things up, hardgainers may benefit from a combination of protein powder, weight gainer, creatine, preworkout multivitamin, fish oil, magnesium, vitamin D and a greens powder supplements to support muscle growth and overall health.

However, supplements should be used as a supplement to a healthy diet and exercise routine, and should always be used under the guidance of a healthcare professional.