6 Best Weight Gain Supplements for Skinny Girls in 2026

Are you tired of eating everything in sight and still not gaining a single pound? You are not alone.

The good news is that the right supplement can change everything. Weight gain supplements give your body the extra calories, protein, and nutrients it needs to build muscle and fill out your frame.

In this post, we reviewed dozens of products and picked the 6 best weight gain supplements for skinny girls in 2026. We also included honest pros and cons, usage tips, and expert advice so you can make the smartest choice for your body.

1. Optimum Nutrition Serious Mass: Best Overall Weight Gainer for Skinny Girls

Last update on 2026-05-22 / Affiliate links / Images from Amazon Product Advertising API

When people talk about the best mass gainer on the market, Optimum Nutrition Serious Mass always comes up. This product has been a bestseller on Amazon for years and for very good reason.

It delivers a massive 1,250 calories per two scoop serving along with 50 grams of protein and 252 grams of carbohydrates. For skinny girls who struggle to eat enough food in a day, this single shake can cover more than half of their daily calorie surplus.

Optimum Nutrition is one of the most trusted supplement brands in the world. Serious Mass contains a blend of whey protein concentrate, whey protein isolate, and calcium caseinate. This combination gives you both fast and slow digesting protein, which supports muscle repair throughout the day and overnight.

The formula also includes creatine monohydrate, glutamine peptides, and 25 essential vitamins and minerals, which means you are not just getting empty calories.

The chocolate flavor is the most popular variety. It mixes well with milk to create an even richer shake with more calories. Many users report mixing it with oat milk, regular milk, or a banana blended smoothie to boost the calorie count further. Vanilla is also available for those who prefer a lighter taste.

One smart tip for skinny women: the full two scoop serving is designed for larger male athletes. Start with a half serving or one scoop and gradually build up. This gives your digestive system time to adjust and reduces the chance of bloating or stomach discomfort.

With over 18,000 reviews on Amazon and a 4.6 star rating, Serious Mass is trusted by real women around the world. It is affordable for the calorie value it provides and is one of the most recognized brands in the weight gain space.

Pros

Delivers 1,250 calories per serving which makes hitting a calorie surplus simple. Contains 50g of high quality protein. Includes creatine and glutamine for muscle recovery. Fortified with 25 vitamins and minerals. Available in multiple flavors. Very cost effective per calorie. Trusted brand with millions of customers worldwide.

Cons

Serving size is large and designed primarily for men. Full serving may cause bloating for women with sensitive stomachs. Contains artificial sweeteners which some users prefer to avoid. Very high in carbohydrates per serving.

2. NAKED Mass Natural Weight Gainer: Best Clean Label Option

Last update on 2026-05-22 / Affiliate links / Images from Amazon Product Advertising API

If you care about what goes into your body, NAKED Mass is the supplement for you. This weight gainer is one of the cleanest on the market. It contains just three core ingredients: whey protein concentrate, casein protein, and maltodextrin derived from organic tapioca. There are no artificial flavors, no artificial sweeteners, no colors, and no additives. What you see on the label is exactly what you get in the tub.

Each serving of NAKED Mass delivers 1,250 calories, 50 grams of protein, and 252 grams of carbohydrates. The protein comes from a blend of whey and casein.

Whey absorbs quickly to kick off muscle protein synthesis right after a workout. Casein absorbs slowly over several hours, which keeps muscles fed even while you sleep. This dual protein blend is one of the main reasons NAKED Mass is so effective for building lean muscle.

The product is GMO free, gluten free, soy free, and certified by Informed Sport. This means it has been tested for banned substances, which makes it safe for women who are competitive athletes. It also means you are getting a cleaner, purer product than most other weight gainers on the shelf.

NAKED Mass comes in unflavored, vanilla, and chocolate. The unflavored version is extremely versatile. You can blend it into smoothies with bananas, peanut butter, oats, and berries without any flavor clash. This makes it a fantastic base for healthy high calorie shakes at home.

The price is slightly higher than other mass gainers but the clean ingredient profile justifies the cost. For skinny girls who are health conscious or who react poorly to artificial ingredients, NAKED Mass is the top choice.

Pros

• Completely free from artificial sweeteners, flavors, and colors.
• GMO free, gluten free, and soy free.
• Dual protein blend for fast and slow digestion.
• Informed Sport certified for purity.
• Unflavored version mixes perfectly into homemade smoothies.
• Ideal for women with food sensitivities.

Cons

• More expensive than most other mass gainers.
• Serving size is very large and calorie dense for smaller women.
• Some users find the unflavored version has a slightly chalky taste on its own.
• May cause bloating if taken too quickly.

3. Dymatize Super Mass Gainer: Best for Maximum Calorie Intake

Last update on 2026-06-01 / Affiliate links / Images from Amazon Product Advertising API

Dymatize Super Mass Gainer is the Amazon’s Choice winner in its category and it earns that badge with ease. This supplement delivers 1,280 calories per two scoop serving along with 52 grams of protein, 245 grams of carbohydrates, and 10.7 grams of BCAAs. If you need maximum calorie density in a single shake, this is the product to grab.

Dymatize is a well respected sports nutrition brand that has been trusted by athletes and bodybuilders for over two decades. The protein blend in Super Mass Gainer includes whey protein concentrate, whey protein isolate, whey protein hydrolysate, and casein.

This multi source protein formula ensures that your muscles receive both immediate and sustained amino acid delivery. The inclusion of 1 gram of creatine monohydrate per serving also gives your muscles added energy during intense training.

The Gourmet Vanilla flavor is particularly popular among women because it is smooth, sweet, and blends well with milk. The chocolate flavor is equally good. Both mix easily in a standard shaker bottle with cold water or milk. Users report minimal clumping compared to other mass gainers.

The BCAA content of this product is worth highlighting. BCAAs, or branched chain amino acids, are the specific amino acids that trigger muscle protein synthesis.

Getting 10.7 grams of BCAAs per serving means your muscles have the exact building blocks they need to repair and grow after every workout. Combined with the high calorie content, this makes Super Mass Gainer a very powerful tool for skinny women who also train.

The product has over 14,000 verified reviews on Amazon with an average rating of 4.5 stars. That level of positive feedback from real buyers says a lot about its reliability and effectiveness.

Pros

• Amazon’s Choice product with 14,000 plus positive reviews.
• Delivers 1,280 calories and 52g of protein per serving.
• Contains 10.7g of BCAAs for muscle recovery.
• Multi source protein blend for sustained amino acid release.
• Includes 1g of creatine for training performance.
• Mixes easily with good taste. Solid value per calorie.

Cons

• Contains artificial sweeteners including sucralose.
• Not suitable for those with dairy or soy allergies.
• Full serving is very large for women with smaller appetites.
• May cause digestive discomfort for some users at full dose.

4. Naturade Weight Gain Nutrition Drink Mix: Best Budget Friendly Option

Last update on 2026-05-22 / Affiliate links / Images from Amazon Product Advertising API

Not every weight gain supplement needs to cost a fortune. Naturade Weight Gain Nutrition Drink Mix is the most affordable product on this list and it performs well above its price point. This drink mix provides a balanced blend of calories, protein, vitamins, and minerals in a simple, easy to use formula.

Each serving delivers around 370 calories and 18 grams of protein. This is lower than the heavy duty mass gainers above but that is exactly what makes it a great option for skinny girls who are just starting out.

Beginning with a smaller calorie boost and gradually increasing your intake is a smarter approach for most women. Jumping into 1,250 calories per shake on day one often leads to digestive discomfort and waste.

The formula is enriched with essential vitamins and minerals including Vitamin C, Vitamin D, calcium, iron, and a full B vitamin complex. For underweight women who may also be deficient in micronutrients, this is a significant advantage. The supplement addresses both calorie needs and nutritional gaps at the same time.

Naturade has been a trusted health supplement brand since 1926. The vanilla flavor is smooth and pleasant. It mixes easily in water or milk.

Many users report adding it to oatmeal, protein smoothies, or baked goods to sneak in extra calories. With over 4,600 reviews on Amazon and a 4.2 star rating, it is a well loved product among women who want gentle, steady weight gain.

This product is ideal for women who are sensitive to very high calorie shakes, those new to supplementation, or anyone looking for a low cost entry point into the world of weight gain supplements.

Pros

• Very affordable price point.
• Gentle calorie boost ideal for beginners and sensitive stomachs.
• Enriched with 20 plus vitamins and minerals.
• Easy to mix in water, milk, or smoothies.
• Trusted brand with nearly 100 years of history.
• Good option for older women or those recovering from illness.
• Smooth vanilla flavor.

Cons

• Lower calorie content than other mass gainers on this list.
• Contains some added sugar.
• May not be sufficient for women with very high calorie needs.
• Protein content is lower than premium mass gainers.
• Not suitable for those with soy or lactose sensitivity.

5. Optimum Nutrition Micronized Creatine Monohydrate: Best for Muscle Building

Last update on 2026-05-25 / Affiliate links / Images from Amazon Product Advertising API

Creatine is one of the most researched and proven supplements in sports nutrition. If your goal is to build lean muscle while gaining weight, creatine monohydrate is an absolute must have in your supplement stack.

Optimum Nutrition Micronized Creatine Monohydrate is the bestselling creatine supplement on Amazon with over 100,000 verified reviews and a 4.6 star rating. That is not a coincidence. It works.

Creatine works by increasing the amount of phosphocreatine stored in your muscles. This gives your muscles more energy during high intensity exercise like weightlifting.

You can lift more weight, do more reps, and push harder every session. Over time, this greater training stimulus leads to more muscle growth. More muscle means a fuller, stronger body and a healthier weight.

This specific product is micronized, meaning the creatine particles have been processed to be smaller. Smaller particles dissolve more easily in water and absorb more efficiently in the body.

Optimum Nutrition’s version is unflavored, which means you can add it to any drink, shake, or even water without altering the taste.

For women, research suggests that creatine also has benefits beyond muscle building. Studies show that creatine may improve bone mineral density, support brain health, and reduce fatigue.

Skinny women who are also naturally low in muscle mass may see especially strong results from adding creatine to their routine.

The recommended dose is 3 to 5 grams per day. Many people start with a loading phase of 20 grams per day split across four doses for five to seven days.

After that, a daily maintenance dose of 3 to 5 grams keeps creatine levels elevated. This product is third party tested, unflavored, and free from unnecessary fillers. It is also one of the most affordable ways to support muscle gain.

Pros

• Bestseller with over 100,000 verified Amazon reviews.
• Proven by hundreds of scientific studies to support muscle growth.
• Micronized for better solubility and absorption.
• Unflavored and easy to add to any shake or drink.
• Very affordable per serving. Third party tested.
• Also supports bone density and brain health.

Cons

• Does not directly add calories so must be paired with a high calorie diet.
• Some users experience initial water retention.
• Requires consistent daily use to maintain results.
• Results are best when combined with resistance training.
• Not ideal as a standalone weight gain solution.

6. CB-1 Weight Gainer Pills: Best Appetite Booster for Skinny Girls

Last update on 2026-05-22 / Affiliate links / Images from Amazon Product Advertising API

Sometimes the biggest barrier to weight gain is not food choices. It is appetite. Many skinny girls simply do not feel hungry often enough to eat the calories they need.

CB-1 Weight Gainer Pills directly address this problem. This clinically tested supplement is designed to boost appetite and slow metabolism, which makes it easier to eat more food naturally throughout the day.

CB-1 is backed by an 8 week clinical study showing that users gained significantly more weight on average than those not taking the supplement.

The formula includes a blend of natural extracts and compounds that are known to stimulate appetite and support weight gain. Each bottle contains 90 capsules which provides a 30 day supply at the standard dose.

This pill based format is one of the most convenient options on this list. You do not need a blender, a shaker bottle, or a kitchen.

You just take a capsule before meals and let the appetite boost do its work. This makes CB-1 ideal for busy women, college students, or anyone who does not have time or interest in preparing large meals or shakes daily.

CB-1 is also popular among women who struggle to digest heavy powder based supplements. If mass gainer shakes leave you feeling bloated or nauseous, switching to a pill format like CB-1 may be a much more comfortable approach. By increasing your appetite, you naturally eat more whole food instead of forcing down another thick shake.

This product has received strong reviews from women users who report noticeable increases in appetite within the first one to two weeks. With a 4.1 star rating and growing popularity, CB-1 is a solid choice for skinny girls who struggle most with eating enough food.

Pros

• Clinically tested with documented weight gain results.
• Easy pill format requires no mixing or preparation.
• Directly addresses low appetite which is a common problem for skinny women.
• No need for a shaker bottle or blender.
• Convenient for travel and busy schedules.
• Suitable for those who dislike the taste or texture of powder supplements.

Cons

• Lower calorie delivery compared to powder based mass gainers.
• Results depend heavily on eating more food after appetite is stimulated.
• Some users report mild nausea in the first few days.
• Higher cost per unit compared to powder options.
• Clinical study was relatively small in scale.

How Do Weight Gain Supplements Work for Women

Weight gain supplements work on a simple principle. Your body gains weight when you consume more calories than it burns. This is called a calorie surplus. Supplements help you reach that surplus more easily by packing a high number of calories into a small, convenient serving.

Most weight gain supplements for women combine three main macronutrients. Protein supports muscle growth and repair. Carbohydrates provide energy and refuel your muscles after training. Fats add calorie density without adding too much bulk to the serving size.

When you pair these supplements with resistance training, the extra calories and protein get directed toward building lean muscle instead of just fat. Research shows that women who strength train and maintain a calorie surplus gain more lean mass and less fat compared to those who eat more without exercising.

Some supplements like creatine work differently. They do not provide many calories directly. Instead, they boost your workout performance so that your muscles face a stronger stimulus to grow. Over weeks and months, this leads to greater muscle size and body weight.

Appetite boosting pills like CB-1 work by influencing hunger signals in the body. This makes you feel hungry more often, which naturally leads to eating more food throughout the day. The result is a higher daily calorie intake without the need to force down food or shakes.

The key principle to remember is this. No supplement works without a supportive diet. You still need to eat real food. Supplements are designed to fill the gaps, not replace meals entirely.

Key Ingredients to Look for in a Weight Gain Supplement

Before you buy any weight gain supplement, read the label carefully. Knowing which ingredients to look for helps you choose a product that actually delivers results.

Whey Protein is the gold standard protein source. It is derived from milk, absorbs quickly, and triggers muscle protein synthesis. Look for at least 25 grams per serving.

Casein Protein is a slower digesting milk protein. Products that combine whey and casein give you both immediate and extended amino acid delivery. This combination supports muscle growth around the clock.

Maltodextrin or Oat Flour are the most common carbohydrate sources in mass gainers. Maltodextrin is a fast absorbing carb that replenishes muscle glycogen quickly after training. Oat flour provides a slower release of energy and extra fiber.

Creatine Monohydrate supports energy production during intense exercise. Even a small amount per serving like 1 to 3 grams can make a meaningful difference in training performance over time.

BCAAs, or branched chain amino acids, are the specific amino acids most directly involved in muscle protein synthesis. Look for products that contain leucine, isoleucine, and valine. A combined BCAA content of 8 to 12 grams per serving is excellent.

Vitamins and Minerals are important for overall health. A good weight gain supplement should include B vitamins for energy metabolism, Vitamin D for bone health, zinc for immune function, and iron for healthy red blood cells.

Avoid products with very long ingredient lists filled with unrecognizable chemicals. Shorter, cleaner ingredient lists almost always mean a better product. Also check for common allergens like soy, dairy, and gluten if you have sensitivities.

How to Use Weight Gain Supplements the Right Way

Using a weight gain supplement incorrectly can slow your results or cause unnecessary side effects. Follow these simple steps to get the most out of your product.

Start with half the recommended serving. Most mass gainers are formulated for large male athletes. A full two scoop serving that delivers 1,250 calories is too much for most women at once. Start with one scoop or half a serving and increase gradually over one to two weeks.

Time your shakes strategically. The best times to take a weight gain supplement are in the morning with breakfast, as a post workout meal within 45 minutes of training, or as a bedtime snack to support overnight muscle repair. Avoid replacing full meals with shakes entirely.

Mix with milk instead of water when possible. Whole milk adds around 150 extra calories, 8 grams of protein, and 8 grams of fat per cup. This is an easy way to increase the nutritional value of your shake without any extra effort.

Blend your shake with real food ingredients. Adding a banana, a tablespoon of peanut butter, a handful of oats, or some frozen berries turns a basic supplement shake into a whole food meal. This boosts calorie content, adds micronutrients, and improves the overall taste.

Be consistent. Weight gain supplements only work if you take them regularly. Set a daily routine and stick to it. Results typically become noticeable after four to six weeks of consistent use combined with training and a good diet.

Track your progress. Weigh yourself once a week at the same time of day. If you are not gaining at least half a pound per week, gradually increase your supplement dose or add more calories from food.

Healthy Eating Tips to Support Your Weight Gain Journey

Supplements are just one piece of the puzzle. What you eat every day has the biggest impact on whether you gain weight. Here are practical tips that work for skinny girls.

Eat more frequently throughout the day. Instead of three meals, aim for five or six smaller meals. Each meal is an opportunity to add more calories. Eating every two to three hours keeps your calorie intake consistent and prevents the hunger dips that lead to missed meals.

Prioritize calorie dense whole foods. Avocado, nuts, seeds, nut butters, whole milk dairy products, eggs, oily fish, whole grains, and legumes are all fantastic for healthy weight gain. These foods pack a lot of energy into small volumes, which is ideal for women with smaller appetites.

Do not fear healthy fats. Fat contains 9 calories per gram compared to 4 calories per gram for protein and carbohydrates. Adding olive oil to meals, eating a handful of nuts as a snack, or blending avocado into your smoothie adds significant calories without a lot of bulk.

Drink your calories. Smoothies, whole milk, fresh fruit juice, and full fat yogurt drinks are all easier to consume than solid food. They do not trigger fullness signals as quickly as chewing solid food. This is why weight gain shakes are such an effective tool.

Prioritize sleep. During sleep, your body releases growth hormone which supports muscle repair and development. Getting seven to nine hours of quality sleep every night maximizes the results from your training and supplementation.

Common Mistakes Skinny Girls Make When Trying to Gain Weight

Even with the best supplements and good intentions, certain habits can sabotage your weight gain efforts. Knowing these mistakes helps you avoid them.

Eating too little protein. Many women focus on adding carbs and fats but forget about protein. Without adequate protein, extra calories tend to be stored as fat rather than built into muscle. Aim for at least 0.7 grams of protein per pound of body weight each day.

Skipping strength training. Cardio burns calories, which is the opposite of what you want. Resistance training tells your body to build muscle with the extra calories you are eating. Without lifting weights or doing bodyweight resistance exercises, most of your calorie surplus will go straight to fat storage.

Expecting results too fast. Healthy weight gain takes time. Gaining half a pound to one pound per week is a realistic and sustainable pace. If you are not seeing changes in a week or two and you give up, you will never reach your goal. Patience is a required ingredient.

Overcomplicating the process. You do not need a perfect meal plan, an exotic supplement stack, or an expensive trainer to start gaining weight. Eating more of the right foods, taking one reliable supplement, and lifting weights three times a week is enough to start seeing results.

Drinking too many low calorie drinks. Diet soda, black coffee, flavored water, and herbal tea are all essentially zero calorie. Replace these with whole milk, protein shakes, or fresh fruit smoothies to add meaningful calories to your daily total without any extra effort.

Inconsistency. This is the biggest mistake of all. Taking a supplement for three days, missing two weeks, then starting again does not work. Build a consistent habit. Think of your supplement as a daily routine just like brushing your teeth.

FAQs

What is the best weight gain supplement for skinny girls in 2026?

Optimum Nutrition Serious Mass is the best overall weight gain supplement for skinny girls in 2026. It delivers 1,250 calories and 50 grams of protein per serving. It is affordable, widely available, and backed by thousands of positive reviews. For women who prefer a clean label option, NAKED Mass is the top alternative.

How long does it take to see results from weight gain supplements?

Most women begin to see noticeable changes in four to six weeks when taking a weight gain supplement consistently alongside a calorie rich diet and regular strength training. The scale may show small increases in the first two weeks as the body adjusts. Visible muscle and body composition changes typically become clear after six to eight weeks.

Can skinny girls use male mass gainers?

Yes, but you should adjust the serving size. Male oriented mass gainers like Serious Mass or NAKED Mass are formulated for larger male athletes. Women should start with half a serving, which is one scoop instead of two. This delivers around 600 calories rather than 1,250. As your appetite and digestive tolerance improve, you can gradually increase the dose.

Do weight gain supplements cause fat gain in women?

Weight gain supplements can contribute to fat gain if you consume a very large calorie surplus without exercise. The best way to minimize fat gain is to combine your supplement with strength training three to four times per week. Exercise tells your body to use extra calories for muscle building rather than fat storage.

Are weight gain supplements safe for women?

Yes, the products on this list are safe for healthy adult women when used as directed. Look for supplements that are third party tested by organizations like NSF International or Informed Sport. Always start with a smaller dose to test your tolerance. If you have any underlying health conditions, consult your doctor before starting any new supplement.

What should I eat alongside a weight gain supplement?

Focus on whole, nutrient dense foods like eggs, chicken, salmon, whole grains, sweet potatoes, avocado, nuts, seeds, full fat dairy, and legumes. Supplement your diet rather than replacing meals with shakes. Think of your supplement as a helpful addition to an already solid diet rather than a substitute for real food.

Can I take creatine as a skinny girl trying to gain weight?

Absolutely. Creatine is one of the safest and most proven supplements available. It supports muscle growth by boosting workout performance. Skinny women who strength train will benefit greatly from adding 3 to 5 grams of creatine monohydrate per day to their supplement routine. It is especially powerful when paired with a mass gainer shake.

Which weight gain supplement is best for women with a sensitive stomach?

Naturade Weight Gain Nutrition Drink Mix and CB-1 Weight Gainer Pills are the best options for women with sensitive stomachs. Naturade delivers a gentler calorie boost with a lower calorie count per serving. CB-1 works in pill form and boosts your natural appetite instead of flooding your system with large amounts of powder.

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Disclaimer: This blog post is for informational purposes only. Always consult a registered dietitian or physician before starting a new supplement regimen, especially if you have an underlying health condition.