

Desertcart purchases this item on your behalf and handles shipping, customs, and support to Japan.
🚀 Bulk smarter, not harder — Serious Mass for serious results!
Optimum Nutrition Serious Mass is a high-calorie weight gainer delivering over 1,200 calories, 50g of protein, and 250g of carbs per 2-scoop serving. Designed for adults aiming to increase muscle mass and overall weight, it includes 20+ vitamins and minerals for immune support and recovery. Ideal for fast metabolisms and intense training, this chocolate-flavored powder blends easily and supports customizable shakes to meet your unique bulking goals.






















| ASIN | B0015R36SK |
| Age Range Description | Adult |
| Allergen Information | Milk, Soy |
| Best Sellers Rank | #1,918 in Health & Household ( See Top 100 in Health & Household ) #2 in Sports Nutrition Weight Gainers #246 in Sales & Deals |
| Brand | Optimum Nutrition |
| Brand Name | Optimum Nutrition |
| Customer Reviews | 4.5 out of 5 stars 34,656 Reviews |
| Diet Type | Vegetarian |
| Flavor | Chocolate |
| Item Dimensions | 6.14 x 6.14 x 9.76 inches |
| Item Weight | 0.9 kg |
| Manufacturer | Glanbia Performance Nutrition |
| Manufacturer Part Number | 1101537 |
| Material Type Free | Caffeine Free |
| Model Name | ON SERIOUS MASS CHOCOLATE 6LB |
| Model Number | 1101537 |
| Number of Items | 1 |
| Package Type Name | Tub |
| Product Benefits | Immune Support, Muscle Growth, Weight Gain |
| Protein | 50 g |
| Protein Source | Whey |
| Recommended Uses For Product | Calorie Increase, Muscle Growth, Post-Workout, Weight Gain |
| Servings per Container | 8 |
| Supplement Formulation | Multi-Supplement |
| Total Servings Per Container | 8 |
| UPC | 748927022995 |
| Unit Count | 96 Ounce |
| Vitamins And Minerals | 0.9, 3.7, 30.0, 5.0, 700.0 milligrams, 410, 80 milligrams |
C**R
Great product and price
Great taste, mixes easy and great price
K**S
It helps a lot
Optimum Nutrition Serious Mass is a great choice for anyone looking to gain weight, build muscle, or increase overall calorie intake. The Chocolate flavor mixes smoothly—especially if you use a blender—and has a rich, dessert-like taste without being overly sweet. Each serving delivers a very high amount of calories, protein, and carbs, which makes it ideal for people with fast metabolisms or those who struggle to eat enough throughout the day. It also includes added vitamins, minerals, and creatine for extra support. The bag is large and lasts a good amount of time depending on how much you use. The powder is heavy, so mixing by hand can be a bit difficult, but blending solves that problem easily. Overall, Serious Mass is effective for healthy weight gain and muscle-building goals. If you need a calorie boost and don’t mind a thick shake, it’s a solid and reliable product.
J**E
If your skinny and have trouble gaining this is for you
Ok so I have been using this product for over a year now. I cycle it in bulking and cutting stages with a pre-workout (Cellucore C4 Extreme) and attempt to consume healthy food in addition to the product. I am an amateur with no professional experience, but this product has worked for me. I am a skinny guy with a very quick metabolism. I train for endurance and strength, NOT mass. If you are a skinny person who has trouble gaining weight I recommend giving this a shot. This is not for body builders who count calories and want to stay lean. Its a weight gainer! I am currently 5'10, 170 lbs. During this cycle I am training 3-4 days a week between 60-90 mins per workout. Like I said I train high endurance and strength, not heavy lifting. In the last 3 months I have gained 15 lbs and lowered my body fat percentage by 4%. I consider this a substantial achievement as I have never been able to put on weight unless I gain lots of fat. When I was cutting I used this as a meal replacement with low calorie intake and actually lost weight taking it! RATIO: The great thing about this product is you can tailor the servings to meet your needs. If you desire more calories and carbs, use more, if you start to notice your getting fat, use less. Start with 1/2 serving a day and increase as needed to reach your desired goals. I generally consume a 1/2 serving mixed with 4-6oz of fat free milk within 30 mins of working out in the morning. I then eat high protein foods throughout the day (Cottage cheese, Greek yogurt, oatmeal (rolled oats, not that instant crap), chicken breast, tuna, brown rice, etc). I try to eat as much clean food as I can throughout the day. I then have another 1/2 serving with milk in the afternoon. TASTE: This product tastes amazing. 1/2 serving mixed with milk comes out like a milkshake, not too thick, not too thin. If you go for the full serving it is very thick and heavy. Its hard to drink that much without throwing up. Split it up into 1/2 servings throughout the day. SIDE EFFECTS: I personally have major gas from this product. Its not horrible, but I have to leave the room throughout the day at work. I anticipate this and take breaks. No big deal. I have had normal bowel movements while taking this product, but I do consume high fiber oatmeal to assist with the digestion. I find myself dropping bricks if I do not consume enough fiber with this product, again, adjust the servings to fit your body needs. FINAL THOUGHTS: Overall I enjoy this product. If you use it as a meal supplement during your cutting stages you may notice you actually LOSE WIGHT while taking this product. I sure did.
R**4
Great addition to a well balanced bulking diet plan
I have been bulking/ cutting for over 20 years and like to use this Mass gain as a meal replacement when bulking. Am I a professional? Hell no, I have to work and do not have the luxury of eating, sleeping, and 2 hour workouts With that said…I am 5’ 11 and 230 with bodyfat percentage depending on whether I am bulking or not. Know your body and what your caloric intake should be. With my body weight and eating 6 meals a day—my bulking caloric intake is 680 calories a meal- 1/2 serving of powder is plenty when mixed with almond milk. If you lose weight while using this like some posts state—-it isn’t the powders fault- this doesn’t work miracles, there are many other aspects to gaining/ maintaining mass Pros: -Contains creatine -Massive amount of calories/carbs/proteins- more than the normal body can process at once when using the serving size of 2 scoops-One scoop provides plenty of calories to repair muscle while you sleep, making this 32 servings instead of 16 -Powder makes it easier to quickly add a meal to your plan when you are tired of eating chicken and rice 5 times a day -mixes very well -It works because it contains a great balance of calories/carbs/protein *** drinking this powder only adds a good calorie ratio to your diet plan, it will not lift the weights for you or eliminate the need to eat 4-5 other meals a day -It is a quality supplement, ranked #4 bulking supplement in 2021 Cons: -It tastes ok…it is a supplement, not a candy bar -Price per serving is mid-range -If using as recommended (2 scoops per serving) it will only last 16 days - I prefer my supplements in contains over bags, this is an easy fix though if you are anal like me Overall, great product I’ve been using for years. This will not turn you into a beast if you are counting on it to work miracles…you still need to have a sufficient diet plan and work you butt off to gain mass. Note- if you are looking to just gain weight this product will definitely work! Take one serving daily and sit on the couch. Do your homework if debating on using a different brand, powders that contain arsenic is something to be very wary of. Good luck in your bulking adventure
C**S
Muscle gain
“I really love this protein because I’m seeing my body earning muscles and the taste is fantastic.
J**T
Gained weight for the first time in all my life... (This is probably the longest review ever but oh well) ...
I was just about making my second order and thought it would be nice to write a review. I'd never been a 'review person' and that's why even though i bought this product in 2014, i never had the time to review properly until now. I've decided to 'give back' too and not be so selfish thus, make it a habit from now. What better way to start off than with the products i've used and appreciated so much? *IF YOU DON'T WANT TO READ EVERYTHING, THIS'S JUST ABOUT MY CONCLUSION TO 1st TIME BUYERS OUT THERE* BASICALLY ; 1. Be sure to workout intensely (esp. your tummy area) to prevent belly fat (cause trust me, it is real) like the plague 2. If you find the mixture too sweet for your liking you could always dilute it with extra milk, some water, or anything other thing that works for you instead of complaining & whining about it and trying to force it down 3. Mixing the chocolate & vanilla flavor (with milk) was something i wish i'd figured out sooner. I couldn't have asked for a better taste. 4. If you're a hard gainer, you can be assured that this product WILL do something for you (if you take it properly and workout well it would do a whole lot more than that). I would know because i'm a serious hard gainer myself and wouldn't even say i 'used it that properly' at all but, in the end i did see noticeable gains and got weight gain compliments for the first time in all my life. I'm sure if you eat well, train really hard, and take this alongside you'd be just more than fine! 5. It has some kind of "very sweet after-taste" though, which lasts for some time. (could be up to 12hrs or more) even if you keep eating things in-between or after you take this. What happens is soon as your mouth becomes empty for some time you start to "feel the taste all over again". I find it very annoying lol but it's the ONLY PROBLEM I HAVE with this product. I'm ok with any other thing. 6. Remember to check with your doctor before taking this (if you have any health issues or are on medication or any other supplements). My "testimony"...(if you're interested) .. I'd never gained above 5 lbs in such a short time my entire life! I weighed 42kg (92 lbs) before i started my weight gain journey in September 2014 and by the time my serious mass got finished (i visited a hospital in January 2015), checked my weight and it said "50kg (110lbs)" I'd never gone past 45kg my entire life! Even when i received those "you've put on weight compliments" when i was younger, highest i prolly was that time was like 43kg. Because of this i thought there was a mistake in the scales they were using at the hospital two year ago. because at that time i wasn't even taking the serious mass anymore cos it had finished about a month or so ago and i'd stopped working out for about a month or so as well. I actually asked the doctor "um,are.. you really sure it's 50?..didn't it just say that because of my clothes or something?" (and i'm someone who'd never asked a doctor "are you sure" ever in my life!) ... I mean i knew i gained some weight all right while i was still 'on track' with this, but then i knew i'd 'stopped my journey' and wasn't even doing anything anymore so i had definitely lost weight again. That's why i was so surprised! I mean, i had a mirror in my house and all ok?, but i guess because i was constantly looking at myself almost every hour on my gain journey i never actually realised that i had gained! It really was 50kg. I had gained 7kg in 2 months!😇 (A HARD-GAINER) i want to stress on that again. LOL I found it really hard to believe so i had to check again during that week with a different scale (for some weird reason i didn't have a scale at home and always had to check outside of the house) lol i really wasn't serious. I checked and got the same measurement to my uttermost surprise. I didn't believe it (still) ... but then after some time i finally got over it & accepted it. That was when it hit me... "Oh, wow..does this mean i gained even more while i was still on the serious mass?" .."umm.. Huh? " And then it hit me again... "this is the first time i've reached 110lbs! ...omg..*my eyes filled with tears* About a year ago that was actually my dream.. to get to 110lbs, and now i'm here! What is this?? How did this even happen?" Well yeah, i WAS extremely confused for a long time. Trust me on that one. WELL ABOUT WORKOUTs; I used to do normal 'home exercises' and i never even went to the gym. I had a workout routine, but because i'm severely anaemic it was always extremely difficult for me to workout properly (and the way i REALLY wanted to). So i did basically some 'soft workouts'. I didn't have dumbbells at the time, so all i did was basically "no dumbbell home exercises" or "workouts without weight" more like it. This is why i was so surprised i gained. I realised that if i'd used weights i would've gained even more. I did squats mainly, (different types of squats) and then some donkey kicks and tummy workouts usually. I normally followed "fitnessblender" videos on youtube, and then some other fitnessmodels' videos that i found. *****I bought 2 chocolates 1 vanilla the first time i ordered this product (yes, it was a huge risk i took but this is just how much i believed in this product even before i tried it for myself). I fell in love with it and knew right from the times i researched about it that it was the RIGHT one for me. That was what i needed tbh, and i just knew. I don't know how but oh well, it did pay off in the end so i guess i was just very lucky***** I never really experienced any form of 'super strength' or felt 'so strong' to do my workouts or anything whenever i used this DURING workout, (and i would not blame it on this because i already had serious low energy problems from my anemic condition), and plus it even says to use it mainly as "between meals, post-workout & before bed" in the description (which i did, but also used it as a pre- and during-workout shake as well) so um, because of that i'm not gonna say it didn't do much or help me with my workouts at all. I used it as a pre-and during workout shake mainly because it had creatine and i thought it would help me workout better and easier (But maybe i didn't experience that much of a change in strength/performance because the creatine content is really small? idk) but then i do know it helped me in all sorts of other ways nonetheless. I RECOVERED FROM MY WORKOUTS REALLY FAST and that was an incredible one. FOR THE TASTES; THE CHOCOLATE; wasn't bad at all when mixed with milk. I used non-fat milk as they recommend, but then always added some extra cup or so of full cream milk after i got my serving (to dilute it a bit). This was good, i liked better the taste it gave me when i did that, but then the downside was that it increased the amount of the shake and so was always a bit harder to push down quickly. THE VANILLA; wasn't bad either. I actually grew more fond of that after sometime when i'd taken the 2 chocolate bags for so long. I liked the taste of that too, but again, it was also way too sweet for my liking when mixed with milk (esp the after-taste). so i'd always add some extra full cream milk/a little water to it to dilute that a bit as well after i'd reached the serving size. After a while, i started mixing both flavors together and IT WAS GOOD! (i only had a few cups of the chocolate left when i figured this out, so i couldn't do that for long, but then with the few days i did that, i never regretted)! I would take one cup of the chocolate flavor, one cup of the vanilla flavor, blend them together, adjust a little with some extra milk, and i'm all good! (I always said to myself "why didn't i think of this earlier?!" lol) In general i never tried any with just water but my brother did once and from the look of things, it's clear they both taste better with milk. I never tried mixing either with other solid stuff like peanut butter, oats & the like because i mostly used to blend them with other liquid nutrition shakes (and they always blended well) but i'll try mixing them with dry oats and some other solid stuff this time and see. I'll be sure to leave an update later! Anyway, to continue my "testimony"; In the beginning i couldn't eat any solid food the rest of the day after i took this in the morning. It filled me up more than a 3 square-meal ever would have so i was always worried i was going to end up relying on that and use that as my 'sole source of nutrition' the entire time. Good thing was.. after a while it SERIOUSLY 'OPENED UP MY STOMACH'' and i was able to eat more than i ever could have handled on my own usually. That made me very happy indeed I knew it was the work of the serious mass because that was by far the most caloric supplement i was taking. The other products i took alongside (more for medical conditions & clinical purposes)were ; Scandishake vanilla -580 calories Enshake chocolate- 600 calories (That was probably why i gained so much but i know the serious mass contributed greatly too!) Oh and, ABOUT THE BLOATING THING PEOPLE SAY.. What i'm gonna say is it is really true. And i realised it when i experienced it myself. (I already believed and was aware from what i'd read even before i bought the items, but i guess i just didn't think it would be that serious!) lol Yeah, the bloating is SERIOUS as well. I had read that you have to workout insanely if you didn't want to end up putting on ONLY FAT so i was already prepared for that. *Only i wasn't as prepared as i thought i was* lol But then to be honest.. with all my 'daily ab workouts' and the like.. i still did have a big tummy while on this mass gainer! lol I probably didn't workout as hard but all i know is i gained weight in the places where i wanted to gain all right, only it came with a lot of belly fat too! I didn't even care at the time though, cause at the time i was far too happy with the gains and knew i could workout later to reduce the belly fat. It was only funny because i'd always been a skinny girl, and i'd never seen my tummy so big (i was actually afraid at some point that it was going to stay that way and it would never go back to the way it was! lol). I mostly felt 'bloated' and i think it's because i wasn't used to having so much calories in my body. I felt so 'heavy' and 'so pregnant' all the time because i was always so full! lol it was a struggle. But i managed to pull through it. After some time of going off my weight gain journey i got my flat tummy back! :) I know what to do this time if i started my journey again so i doubt that would happen anymore! I will train harder than i did last time so i'm very well prepared i must say. So should you! 😊 I would say it was fun though! The whole experience was fun and exciting as i'd never had that much CHALLENGE thrown at... well my body..ever! I was new to working out and all these mass gainers and the like. I gradually grew from there over time.. and now i know so much more than i didn't (two years ago) about mass gainers, workout routines and the like. I'm still attached to serious mass (yes of course, the love is still there!) and i would keep on buying until i've reached the goal i've always wanted to reach. (which is around 60kg or 132 lbs. I weigh 40kg now, that's about 88lbs yeah, unfortunately.. i lost all that weight in the course of just 1 year and i'm 21 now (which means very much underweight since i'm only 5'3) which is why i'm getting myself more bags of this product)! Funny thing's, i'm not even in the United States or Canada or the UK. I'm not in a country where i could easily get this product when and if i want. But then i still manage, and do all i can to get it every time (If i told you how much trouble i go through and how much money it costs me every time, you would marvel!) The number of things i could buy with the amount i spend just trying to get 2 bags of serious mass down to where i am... it's ridiculous but oh well, when something's worth it you're never really bothered so this should tell you just how much useful this product is! Those of you who can just order it and get it the next day or two (and at this price with no other extra costs), be very lucky and make good use of it. (I'm not getting anything for this review just so you know, i do not know the company or haven't had any agreements to do this with whatsoever. I took time & wrote this review wholeheartedly just so future buyers would know what a great product this is just in case they were having any doubts) 😊 For hard gainers... i'll DEFINITELY recommend!
J**G
Protein powder
Good protein powder.
T**R
What They Don't Tell You
What they tell you. It tastes great and is a good supplement to build mass. What they don't tell you. Each serving consist of 2 huge heaping scoops of powder and 24 ounces of fluid (water or milk). This combination results in 48 ounces of liquid delight that they claim is a single serving. On what planet is 48 ounces a single serving? To put this in perspective, that is 2 full to the brim Shaker bottles that are intended to be consumed as one serving. 340 grams of powder from one serving translates into 3/4 of a pound of powder. Again to put this into perspective, the huge tub of powder you will recieve equals ONLY 8 advertised servings. The other thing they don't tell you is the powder is so fine and gummy that the only way to prepare the drink is to use a full sized blender. No Shaker bottles here. Preparing this mix is a mess. The powder is so fine that it creates a gummy mess that adheres to the side of the blender like Venom on Eddie Brock. Prepare to spend a significant amount of time coaxing the paste free to get it to properly mix. Great protein mix, but I sometimes I feel like it would be easier to eat 5 chicken breasts too reach the same calorie goal, than to put down 48 ounces. I realize that it can be broken up throughout the day, but so can multiple meals. There is also the option of using another protein supplement with a realistic serving size, multiple times a day. In the end, I feel like that is all they have done with this product. They have combined a multiple dose, throughout the day protein powder into a single serving, trying to advertise it as a solution that they obviously have not solved.
J**E
Schokolade lecker, hochwertige Carbs und keine Klumpen. Guter Weight Gainer!
Als Hardgainer, der schlecht an Gewicht zulegt, habe ich mich, wegen der immensen Zeitersparnis, für einen weight gainer entschieden. Da die meisten weight gainer total uberzuckert sind und man dadurch nur Fett einlagert, habe ich nach einem Produkt mit sehr wenig Zucker und hochwertigen Kohlenhydraten gesucht. Serious mass von Optimum nutrition gibt mit genau das was ich gesucht habe. Zu den hochwertigen Carbs sind noch viele Proteine und Aminosäuren wie glutamin enthalten. Zum Geschmack: ich habe viele Rezensionen gelesen und habe herausgefiltert, dass Schokolade wohl ganz ok sein soll. Somit habe ich auch Schokolade bestellt und kann sagen,dass es mehr als okay ist. Definitiv schokoladig, nicht zu süß und überhaupt nicht mehlig! Auch das Klumpen kann ich nicht bestätigen. Ich habe es mit einem Mixer mit Wasser gemacht und hatte 0,0 Klumpen. Mit Milch 0,3% war es genauso. Da muss man evtl die Schuld auf den Mixer und nicht auf das Produkt schieben! Krass ist natürlich der Messbecher. Ich habe noch nie so einen großen Messbecher gesehen, den ich sogar zweimal voll machen muss. Aber ok,man will ja auf die Kalorien kommen. Durch die Menge die man für einen shake braucht, wird die Dose also relativ schnell leer sein. Das ist das einzig negative! Ansonsten ist dies der hochwertigste weight gainer, den ich kenne, der nicht durch Zucker, sondern durch hochwertige Kohlenhydrate glänzt. Ich komme damit prima auf meinen Überschüss und wenn ich nach dem Training mal nicht kochen kann, bin ich durch den Shake nahezu perfekt versorgt, denn er füllt meine Glykogen - und Proteinspeicher. Geschmack in Schokolade ist lecker! Werde ich wieder kaufen!!
A**R
ガリガリの人に見て欲しい
今まで代謝が良すぎて全然太らなくてこれを試してみました。僕の場合1日に1200kcalを2回摂ってるので正直キツイです。味も一気に飲むと甘ったるすぎるので分けて飲むのをおすすめします。ほんとにガリガリで少食でも無いのに178cmの53kgでした。普段の食事等もがんばって1日だいたい3400kcalくらい摂れるようにしていたら3週間で60kgまで増えました。これからもこれを飲んでもっと増やします。僕のように自分を変えたい人にとっては最高の商品だと思います!
M**T
Top Weight Gainer – wirkt und schmeckt 👍
Sehr gutes Produkt! Löst sich gut auf, schmeckt angenehm und hilft beim Zunehmen und Muskelaufbau. Klare Empfehlung für alle, die Masse aufbauen möchten.
B**O
Gainer
Ottimo prodotto
J**O
Effective product for underweight people
I've always been slim/athletic but after a serious illness I went under nine stone and stayed there (I'm five foot ten). I have a fast metabolism and eating the required amount of food to healthily gain weight was extremely difficult to sustain. I tried eating junky high calorie snacks but realised it was a stupid way of trying to gain weight. So after buying this product I went straight in and tried to drink a full serving - mistake! I managed it but felt quite ill afterwards. I highly recommend you start with half or even a quarter serving to begin with, just until your stomach adapts. It's now two weeks later and with trial and error I've found that splitting a full serving into three is best for me. One in the morning, one after lunch, one in the evening. I use full fat milk, ice cream and a banana to boost the calories per full serving to over 2000, and I find a blender works great to give a nice semi-thick smooth shake. When I started a fortnight ago I weighed 8 stone 12, I now weight 9 stone 8, so I've gained roughly 10 pounds in two weeks, with fluctuations along the way. I've just bought another 5.4kg bag and plan to continue to steadily gain until I reach around 11 stone. I bought some weights and with some advice I've started a light exercise programme with the aim of turning the energy to muscle and shaping my body a bit. I have more modest aims than many who take this supplement, I'm not looking to build huge muscles and train super hard, but if you're like me - underweight and a bit unfit - then I recommend this product along with some sort of exercise programme so it doesn't just go straight to your belly. It really does promote weight gain, I've been very pleasantly surprised with the results, and will continue to use the product as needed in order to achieve and maintain my target weight. The chocolate flavour is very pleasant, if a little sweet, and I now have no problem ingesting what I need to in order to gain weight. It may seem expensive, but at £2.50 a day it works out an easy, reliable and cost effective way to supplement your diet without resorting to less healthy alternatives. It works for skinny old me, and I don't see any reason why it shouldn't work for skinny old you! :) Edit - it's now 22 days after I first used the product and I'm now just over ten stone, so that's 16lb in 22 days. People are commenting on the difference and it's done wonders for my energy levels and appetite. So all in all I can't recommend this product any more highly, it genuinely works. Can't say fairer than that! Last update - I'm now at my target weight of 11st, it's taken 54 days for me to put on 30lbs - two stone two pounds in just under two months. That's beyond what I expected. If I could give a final note it would be to watch your body fat as without exercise this product will raise it quite easily. I'm now going to reduce my servings to maintain this weight, with my new increased appetite it's possible that I soon won't need a supplement at all. So that's me signing off, a bit heavier and a lot happier!
Trustpilot
3 weeks ago
2 months ago