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Price comparison

Price data powered by pricesAPI.io

Last updated at 08/06/2026 17:23:21

Please note: price history and price alerts are not available for some stores, including Amazon.com.au.
Amazon.com.au

$149.95

Optimum Nutrition Serious Mass Gainer Protein Powder, Banana, 12 Pound

Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!

Southern-Workout

$135.99

Optimum Nutrition Serious Mass Protein 12LB / Strawberry

Delivery $12.50

Oxygen Nutrition

$144.40

Optimum Nutrition Serious Mass, 5.4kg / Vanilla

Free same-day delivery

eBay.com.au

$144.95

Optimum Nutrition Serious Mass - 12lb - Chocolate

Free delivery

Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!

eBay.com.au

$254.99

Serious Mass Protein Powder, Mass Gainer, 1250 Calories Per Serve,

Free delivery

Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!

eBay.com.au

$255.99

Serious Mass Protein Powder Gainer, Chocolate, 5.44kg

Free delivery

Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!

Mr Vitamins

$144.95

Optimum Nutrition Serious Mass

Free delivery

Chemist Direct

$149.95

Optimum Nutrition Serious Mass Chocolate 5.44kg

Free delivery between Thu – Mon

Chemist Direct

$149.95

Optimum Nutrition Serious Mass Vanilla 5.44kg

Free delivery between Thu – Mon

Pharmacy Online

$149.95

Optimum Nutrition Serious Mass Chocolate 5.44kg

Free delivery between 11–16 June

Price history

Price history

Please note: price history and price alerts are not available for some stores, including Amazon.com.au.

Reviews

9 March 2022jorge.p

originally posted on influenster.com

I've been trying to gain weight for about 4 years, being 6ft and weighting 9st (57kg) and I was very skinny for my form, I had decided to go hard this time and my gym friend recommended this particular powder over other ones I had been previously trying as he said it had helped people with similar issues to gain weight. So I started Gym again with this shake (two scoops on a morning on rest days and 2x2 scoops morning and after gym sessions) and within a week started to notice results. Now results wont just come from gym and this shake if you're like me, I've had to stick between 3500 - 5000 calories daily, with high carb high protein foods (as lean as possible meat) and a healthy side of multivitamins. The result is I gained 11 pounds (5kg) in 4 weeks, which for me ... MoreI've been trying to gain weight for about 4 years, being 6ft and weighting 9st (57kg) and I was very skinny for my form, I had decided to go hard this time and my gym friend recommended this particular powder over other ones I had been previously trying as he said it had helped people with similar issues to gain weight. So I started Gym again with this shake (two scoops on a morning on rest days and 2x2 scoops morning and after gym sessions) and within a week started to notice results. Now results wont just come from gym and this shake if you're like me, I've had to stick between 3500 - 5000 calories daily, with high carb high protein foods (as lean as possible meat) and a healthy side of multivitamins. The result is I gained 11 pounds (5kg) in 4 weeks, which for me was mind boggling. So if you feel it's extremely hard to gain weight and are looking around, contemplate giving this a try, eat healthy and work out, I can almost promise this will work. It is hard work though, and it will cost a bit more monthly, but I feel better right now mentally and physically than I ever have in my life.

Good
25 September 2022iHerb Customer

originally posted on iherb.com

The package, the taste and quality of this mass gainer is great, like drinking a smoothie. I usually take 2 scoop after my workout which can easily allow me to absorb enough calories and protein for my bulk. It is also cost effective. After taking this gainer, I have gained 30lbs in 3 months. Definitely will reorder and recommend to others who have no time in prepping their food and would like to bulk in a short period of time. However, if you have time to prep your own food, you should not take this mass gainer as there is a lot of sugar inside the gainer.

Great at gaining weight and strength, especially if you are a hard gainer
4 May 2022Markus

originally posted on gnc.com

Serious Mass has helped me to go from 159 lbs. to 167 lbs. in about 2 months, and that is with half a serving a day. I went from 153 lbs. to 159 lbs. by eating more and strength training and then hit a wall. At 55 years and 5'9" I simply couldn't eat the amount of food required to gain more weight and strength. And as long as I still see gains while working out I will continue to go with half a serving a day.I blend a handful of frozen strawberries and frozen sliced banana with 12 oz of cold water until smooth, add half a serving of Serious Mass, blend it and then add 12 oz of whole milk for another short burst. This results in a good tasting drink that is not frothy. I take it to work in a thermos bottle and usually finish it within 5 hours. Blending it with just ... MoreSerious Mass has helped me to go from 159 lbs. to 167 lbs. in about 2 months, and that is with half a serving a day. I went from 153 lbs. to 159 lbs. by eating more and strength training and then hit a wall. At 55 years and 5'9" I simply couldn't eat the amount of food required to gain more weight and strength. And as long as I still see gains while working out I will continue to go with half a serving a day.I blend a handful of frozen strawberries and frozen sliced banana with 12 oz of cold water until smooth, add half a serving of Serious Mass, blend it and then add 12 oz of whole milk for another short burst. This results in a good tasting drink that is not frothy. I take it to work in a thermos bottle and usually finish it within 5 hours. Blending it with just water left an aftertaste that I didn't like too much.I have been using ON Whey Protein since I started working out, one serving with 12 oz of whole milk in the morning with breakfast, and then one serving with 8 oz of cold water 30 minutes after my workout in the evening. Serious Mass is a great addition that has been helping me meet my daily protein goals, gain weight and strength at the same time.

Specification

Protein50g
Calcium590mg
Iron8mg
Selenium70mcg

Price comparison

Updated 1 day ago
Please note: price history and price alerts are not available for some stores, including Amazon.com.au.
Amazon.com.au

$149.95

Optimum Nutrition Serious Mass Gainer Protein Powder, Banana, 12 Pound

Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!

Southern-Workout

$135.99

Optimum Nutrition Serious Mass Protein 12LB / Strawberry

Delivery $12.50

Oxygen Nutrition

$144.40

Optimum Nutrition Serious Mass, 5.4kg / Vanilla

Free same-day delivery

eBay.com.au

$144.95

Optimum Nutrition Serious Mass - 12lb - Chocolate

Free delivery

Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!

eBay.com.au

$254.99

Serious Mass Protein Powder, Mass Gainer, 1250 Calories Per Serve,

Free delivery

Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!

Price history

Price history

Please note: price history and price alerts are not available for some stores, including Amazon.com.au.

Reviews

9 March 2022

I've been trying to gain weight for about 4 years, being 6ft and weighting 9st (57kg) and I was very skinny for my form, I had decided to go hard this time and my gym friend recommended this particular powder over other ones I had been previously trying as he said it had helped people with similar issues to gain weight. So I started Gym again with this shake (two scoops on a morning on rest days and 2x2 scoops morning and after gym sessions) and within a week started to notice results. Now results wont just come from gym and this shake if you're like me, I've had to stick between 3500 - 5000 calories daily, with high carb high protein foods (as lean as possible meat) and a healthy side of multivitamins. The result is I gained 11 pounds (5kg) in 4 weeks, which for me ... MoreI've been trying to gain weight for about 4 years, being 6ft and weighting 9st (57kg) and I was very skinny for my form, I had decided to go hard this time and my gym friend recommended this particular powder over other ones I had been previously trying as he said it had helped people with similar issues to gain weight. So I started Gym again with this shake (two scoops on a morning on rest days and 2x2 scoops morning and after gym sessions) and within a week started to notice results. Now results wont just come from gym and this shake if you're like me, I've had to stick between 3500 - 5000 calories daily, with high carb high protein foods (as lean as possible meat) and a healthy side of multivitamins. The result is I gained 11 pounds (5kg) in 4 weeks, which for me was mind boggling. So if you feel it's extremely hard to gain weight and are looking around, contemplate giving this a try, eat healthy and work out, I can almost promise this will work. It is hard work though, and it will cost a bit more monthly, but I feel better right now mentally and physically than I ever have in my life.

jorge.p originally posted on influenster.com
Good
25 September 2022

The package, the taste and quality of this mass gainer is great, like drinking a smoothie. I usually take 2 scoop after my workout which can easily allow me to absorb enough calories and protein for my bulk. It is also cost effective. After taking this gainer, I have gained 30lbs in 3 months. Definitely will reorder and recommend to others who have no time in prepping their food and would like to bulk in a short period of time. However, if you have time to prep your own food, you should not take this mass gainer as there is a lot of sugar inside the gainer.

iHerb Customer originally posted on iherb.com
Great at gaining weight and strength, especially if you are a hard gainer
4 May 2022

Serious Mass has helped me to go from 159 lbs. to 167 lbs. in about 2 months, and that is with half a serving a day. I went from 153 lbs. to 159 lbs. by eating more and strength training and then hit a wall. At 55 years and 5'9" I simply couldn't eat the amount of food required to gain more weight and strength. And as long as I still see gains while working out I will continue to go with half a serving a day.I blend a handful of frozen strawberries and frozen sliced banana with 12 oz of cold water until smooth, add half a serving of Serious Mass, blend it and then add 12 oz of whole milk for another short burst. This results in a good tasting drink that is not frothy. I take it to work in a thermos bottle and usually finish it within 5 hours. Blending it with just ... MoreSerious Mass has helped me to go from 159 lbs. to 167 lbs. in about 2 months, and that is with half a serving a day. I went from 153 lbs. to 159 lbs. by eating more and strength training and then hit a wall. At 55 years and 5'9" I simply couldn't eat the amount of food required to gain more weight and strength. And as long as I still see gains while working out I will continue to go with half a serving a day.I blend a handful of frozen strawberries and frozen sliced banana with 12 oz of cold water until smooth, add half a serving of Serious Mass, blend it and then add 12 oz of whole milk for another short burst. This results in a good tasting drink that is not frothy. I take it to work in a thermos bottle and usually finish it within 5 hours. Blending it with just water left an aftertaste that I didn't like too much.I have been using ON Whey Protein since I started working out, one serving with 12 oz of whole milk in the morning with breakfast, and then one serving with 8 oz of cold water 30 minutes after my workout in the evening. Serious Mass is a great addition that has been helping me meet my daily protein goals, gain weight and strength at the same time.

Markus originally posted on gnc.com
Great taste and texture
8 November 2022

I got this product a few days ago. It tastes very good, unlike most shakes. When I blended it with milk and water, it was smooth (the thickness really depends on how much water-or whatever fluid-you add to it) and very easy to drink. It kinda tastes and smells like vanilla milkshake. I blended 2 heaped scoops with milk and water. However, I felt bloated and had slight abdominal discomfort almost all through the day. I guess I should have started with one scoop (as suggested for new users). All in all it seems good, I would just need to reduce to one scoop and keep using.

Anjie originally posted on Holland & Barrett
Ridiculously Overpriced Product You Can Avoid
13 September 2022

This is garbage. Do the math by reading the label. It costs a ton of money to get less nutrition than the Equate brand. Again - don't take my word for it - READ THE LABEL AND COMPARE. You need 322 grams of this crap to get 50 grams of protein. Read the Equate brand - you need about 1/5th of that amount.$28 to get four (4) servings. Do the math - that's $6.50 per serving. No big value there.You are paying for marketing. I won't buy this company's products any more now that I realize it is only about the money and I stupidly bought this because I was in a hurry.

Clinton originally posted on walmart.com
Seriously works!
12 October 2022

I've been using this product (chocolate) for years to add more muscle quicker while I work out. I have gained 25 lbs of muscle as a result :) It tastes great too. I mix mine with milk, vanilla ice cream, and 3 scoops of Serious Massin a 72 oz. Ninja blender. I highly recommend this product and GNC sells it at a good price. Oh, and it comes with a scoop in the bag. Save your scoop as sometimes but not very often the one you get somehow gets sunk down to the bottom of the bag. It is a very fine powder and you'll make a mess trying to get that buried scoop out.

John originally posted on gnc.com
Solid Meal Replacement!
10 March 2022

Ok - straight up, I am an ectomorph. Gaining weight at any level is a challenge - I just cannot eat that much. This significantly helps me get the calories with the right macromix. I only take 1-serving (2-scoops) per day, split into 2-shakes (1-scoop right after I wake up and 1-scoop about 1h-1/2 b4 my workout). Over 4-weeks I have gained 2lbs a week. I have added over an 1.5" on every body part with most being in the 2" range (my shoulders jumped a massive 4") during the 4-weeks of using this. It mixes with water pretty well...there are a few chunks when I get a little sloppy and not shake it enough, but not too bad. As for flavor, I definitely prefer the chocolate. I goofed on my last order and got 2-choc/pb... not horrible but not great. This has creatine in it, ... MoreOk - straight up, I am an ectomorph. Gaining weight at any level is a challenge - I just cannot eat that much. This significantly helps me get the calories with the right macromix. I only take 1-serving (2-scoops) per day, split into 2-shakes (1-scoop right after I wake up and 1-scoop about 1h-1/2 b4 my workout). Over 4-weeks I have gained 2lbs a week. I have added over an 1.5" on every body part with most being in the 2" range (my shoulders jumped a massive 4") during the 4-weeks of using this. It mixes with water pretty well...there are a few chunks when I get a little sloppy and not shake it enough, but not too bad. As for flavor, I definitely prefer the chocolate. I goofed on my last order and got 2-choc/pb... not horrible but not great. This has creatine in it, so I know that is adding a bit to the size growth. But, mostly I love it because it's and easy 1200 calories (2-meals out of 6 for me).

Dave originally posted on bodybuilding.com
Truly awful taste.
26 April 2023

I chose the chocolate flavour because I thought it might taste more natural than the fruit flavoured alternatives. I was wrong. It had a really disgusting synthetic taste, so bad that I could only swallow one small mouthful of the smoothie I’d made to the instructions given. No way could I ever eat enoughof it to help me gain weight. I would rather die of starvation than have any more of this appalling stuff.I binned the rest of the HUGE plastic bottle of horrible powder. If it had been available in a smaller trial packet, I would have wasted less money when testing it.

Ginnychick originally posted on Holland & Barrett
Worked for me!
23 March 2022

I went through a little rough patch in life and I stopped eating, so I lost a lot of weight. I got this stuff and I went from 135 to 160 in about a month and a half. I did work out about 5-6 times a week (PPL, rest, repeat), and I was eating several meals a day as well (about 3,000+ Kcal a day). This just made it easier for me to get all my calories in for the day fairly easily considering I was having such a hard time eating. I mix 1 scoop of powder with 2 cups of Fairlife 2% milk, and that's about 50g of protein per shake. Remember that this is a supplement, and it should do exactly that "supplement". Don't just rely on this product to gain weight because you still have to eat real food as well. Other than that the flavor is great, I get the chocolate. Use a ... MoreI went through a little rough patch in life and I stopped eating, so I lost a lot of weight. I got this stuff and I went from 135 to 160 in about a month and a half. I did work out about 5-6 times a week (PPL, rest, repeat), and I was eating several meals a day as well (about 3,000+ Kcal a day). This just made it easier for me to get all my calories in for the day fairly easily considering I was having such a hard time eating. I mix 1 scoop of powder with 2 cups of Fairlife 2% milk, and that's about 50g of protein per shake. Remember that this is a supplement, and it should do exactly that "supplement". Don't just rely on this product to gain weight because you still have to eat real food as well. Other than that the flavor is great, I get the chocolate. Use a blender and you'll have no issues with the texture. Oh, it did make me gassy and bloated at times, so you might want to pick up some GasX and some probiotics as well. Good luck!

originally posted on bodybuilding.com
Works great - beware of potential health issues
17 October 2021

I had been underweight my entire life, really struggling to gain weight. This product worked exactly as advertised, helping me gain weight and at a very affordable price when subscribing. Tasted great, especially when combined with full fat yoghurt, milk & almond butter.HEALTH WARNING - soon after using this product, my periodic blood test showed a significant decline in kidney function. 3 months later, similar results. My consultant mentioned that these results are common in younger people who take supplementary weight/muscle gain products. I immediately cancelled my subscription to this product. Fast forward to today and after another blood test my kidney function has returned to normal.My review score reflects the product itself, affordability, and how well ... MoreI had been underweight my entire life, really struggling to gain weight. This product worked exactly as advertised, helping me gain weight and at a very affordable price when subscribing. Tasted great, especially when combined with full fat yoghurt, milk & almond butter.HEALTH WARNING - soon after using this product, my periodic blood test showed a significant decline in kidney function. 3 months later, similar results. My consultant mentioned that these results are common in younger people who take supplementary weight/muscle gain products. I immediately cancelled my subscription to this product. Fast forward to today and after another blood test my kidney function has returned to normal.My review score reflects the product itself, affordability, and how well it serves its purpose. However, please be aware of potential longer term health consequences.

Adam originally posted on Holland & Barrett

Specification

Protein50g
Calcium590mg
Iron8mg
Selenium70mcg

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Optimum Nutrition - Serious Mass Banana - 12 lbs.
Optimum Nutrition - Serious Mass Banana - 12 lbs.

Optimum Nutrition - Serious Mass Banana - 12 lbs.

$135.99

(32,822 reviews)

Putting on mass has never been so easy with Optimum Nutrition Serious Mass. This weight gainer powder contains a whopping 1,250 calories per serving, with 2 massive 167g scoops packing 50g of blended protein including Whey Concentrate and Isolates, as well as casein and egg proteins. Plus over 250g of carbohydrates, no added sugar, as well as creatine, glutamine and glutamic acid to support strength and recovery, look no further if you want to take your muscle building to the next level. Plus with as little as 7g of fat and enhanced with 25 vitamins and minerals, you can forget dirty bulking to increasing your calorie intake, and reach for a tub of Optimum Nutrition Serious Mass instead, to flood your body with muscle building nutrients capable of sky-rocketing your daily intake of proteins and carbohydrates. Available in Banana, Vanilla and Chocolate, prepare for one of the most delicious and best textured shakes on the market. Don’t forget to mix with low fat milk to step up your calorie game to the next level!

Putting on mass has never been so easy with Optimum Nutrition Serious Mass. This weight gainer powder contains a whopping 1,250 calories per serving, with 2 massive 167g scoops packing 50g of blended protein including Whey Concentrate and Isolates, as well as casein and egg proteins. Plus over 250g of carbohydrates, no added sugar, as well as creatine, glutamine and glutamic acid to support strength and recovery, look no further if you want to take your muscle building to the next level. Plus with as little as 7g of fat and enhanced with 25 vitamins and minerals, you can forget dirty bulking to increasing your calorie intake, and reach for a tub of Optimum Nutrition Serious Mass instead, to flood your body with muscle building nutrients capable of sky-rocketing your daily intake of proteins and carbohydrates. Available in Banana, Vanilla and Chocolate, prepare for one of the most delicious and best textured shakes on the market. Don’t forget to mix with low fat milk to step up your calorie game to the next level!

Optimum Nutrition - Serious Mass Banana - 12 lbs.

(32,822 reviews)

Putting on mass has never been so easy with Optimum Nutrition Serious Mass. This weight gainer powder contains a whopping 1,250 calories per serving, with 2 massive 167g scoops packing 50g of blended protein including Whey Concentrate and Isolates, as well as casein and egg proteins. Plus over 250g of carbohydrates, no added sugar, as well as creatine, glutamine and glutamic acid to support strength and recovery, look no further if you want to take your muscle building to the next level. Plus with as little as 7g of fat and enhanced with 25 vitamins and minerals, you can forget dirty bulking to increasing your calorie intake, and reach for a tub of Optimum Nutrition Serious Mass instead, to flood your body with muscle building nutrients capable of sky-rocketing your daily intake of proteins and carbohydrates. Available in Banana, Vanilla and Chocolate, prepare for one of the most delicious and best textured shakes on the market. Don’t forget to mix with low fat milk to step up your calorie game to the next level!

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$135.99 - $255.99

in 19 offers

The lowest price for Optimum Nutrition - Serious Mass Banana - 12 lbs. right now is $135.99 at Southern-Workout, compared across 15 retailers.

The all-time low was $56.99 on 15 Oct 2025 — today's price is 139% above the lowest ever. It has been notably cheaper before — worth setting a price alert.

Prices last updated 8 June 2026.

Size:

2.8 kg
2.72kg
2.73 kg
6 lbs
12 lbs