Which Liquids Have Protein? A Comprehensive Guide

January 8, 2026 •

4 min read

Did you know a single glass of cow's milk can contain around 8 grams of high-quality, complete protein? This fact highlights the many liquid sources available for those seeking to increase their protein intake, but the list extends far beyond traditional milk. Depending on your dietary needs and preferences, a variety of beverages can help you achieve your daily protein goals.

Quick Summary

This guide examines a variety of liquid protein sources, from dairy and plant-based milks to specialized protein shakes and broths, to help you make informed dietary choices.

Key Points

Cow's milk is a complete protein: A single glass provides around 8g of complete protein, containing all essential amino acids.
Soy milk is the most protein-rich plant milk: It is the closest plant-based option to cow's milk in terms of protein content.
Protein powders offer a concentrated source: Whey, casein, and plant-based powders provide a quick and efficient way to consume high-quality protein.
Bone broth provides collagen protein: A savory option, bone broth contains significant protein derived from collagen.
Kefir adds protein and probiotics: This fermented dairy drink offers a protein boost along with benefits for gut health.
Smoothies can be customized for protein: You can easily increase a smoothie's protein content by adding Greek yogurt, nut butters, seeds, or protein powder.

Protein is an essential macronutrient vital for building muscle, repairing tissues, and supporting overall health. While solid foods are a primary source, liquid proteins offer a convenient and easily digestible alternative for various lifestyles, including athletes, individuals recovering from surgery, or those simply looking for a nutritious snack.

Dairy-Based Protein Liquids

Dairy products are well-known for their high-quality protein content, which is comprised of two main types: casein and whey.

Cow's Milk: A Complete Protein Source

Cow's milk is considered a complete protein, meaning it contains all nine essential amino acids. A single cup (8 oz) typically provides around 8 grams of protein, and this amount remains consistent across different fat percentages, from whole to skim milk. Lactose-free versions are widely available for those with dietary intolerances.

Greek Yogurt and Kefir Drinks

Fermented dairy drinks offer both protein and probiotics for gut health. Greek yogurt drinks and kefir smoothies can provide a substantial protein boost. For example, some kefir products contain around 8 to 9 grams of protein per cup.

Plant-Based Protein Alternatives

For those following a vegan or dairy-free diet, several plant-based liquids provide a good source of protein.

Soy Milk: A Top Plant-Based Choice

When it comes to plant-based milks, soy milk is a clear winner for protein content. It offers a complete protein and can provide anywhere from 7 to 10 grams per cup, making it the closest plant-based match to cow's milk.

Other Plant Milk Options

While soy milk leads the pack, other plant milks also contain protein, though often in smaller amounts. Oat milk typically contains 2-4 grams per cup, while hemp milk offers a more comparable 8-10 grams, and almond milk is generally the lowest with just 1 gram per cup. For higher protein, fortified varieties are often available.

Specialized Protein Shakes and Powders

For a highly concentrated and convenient protein source, supplements are a popular choice.

Protein Powder Categories

Protein powder comes in several forms to suit different needs:

Whey Protein: Fast-digesting and rich in amino acids, it's ideal for post-workout muscle recovery.
Casein Protein: A slow-digesting protein, it provides a steady release of amino acids over several hours, making it perfect for nighttime consumption.
Plant-Based Protein: Made from sources like pea, rice, or hemp, these powders offer a high protein content without animal products.

Ready-to-Drink Shakes

Brands like Fairlife and Premier Protein offer pre-mixed, high-protein shakes that provide a convenient, on-the-go option.

Savory High-Protein Liquids

For a different flavor profile, savory liquids can also contribute to your protein intake.

The Nutrient-Dense Bone Broth

Made by simmering animal bones, bone broth draws out collagen, resulting in a protein-rich liquid. A standard cup can provide between 8 and 10 grams of protein. It can be consumed on its own or used as a base for soups and stews.

Comparison of High-Protein Liquids


Liquid Type	Protein (g/cup)	Pros	Cons
Cow's Milk	~8g	Complete protein, rich in calcium and vitamin D	Contains lactose, not suitable for vegans
Soy Milk	7–10g	Complete protein, vegan-friendly, good source of nutrients	Flavor preference varies, not suitable for soy allergies
Kefir	8–9g	High protein, rich in probiotics for gut health	Fermented flavor is not for everyone, contains dairy
Bone Broth	8–10g	High in collagen protein, savory taste, low-calorie	Taste can be polarizing, homemade takes time
Protein Shake	20–30g+	Highly concentrated, convenient, muscle recovery focus	Can contain added sugars or artificial sweeteners

DIY Smoothies for a Protein Boost

Creating your own high-protein smoothie allows for maximum control over ingredients. Begin with a protein-rich liquid base like cow's milk, soy milk, or a protein shake. Then, add other sources to boost the protein and nutrient profile. Good additions include nuts, seeds, nut butters, and silken tofu.

Conclusion: Making the Best Liquid Protein Choice

Numerous liquids can be a valuable part of a protein-focused diet. From nutrient-dense dairy and plant-based milks to highly concentrated protein shakes and savory bone broths, the best choice depends on your personal health goals, taste, and dietary restrictions. By understanding the protein content and benefits of each option, you can easily incorporate them into your daily routine. For further reading on nutritional needs, consult a reliable health resource like Mayo Clinic's guidelines on protein shakes.

Making the Best Liquid Protein Choice

Frequently Asked Questions

No, protein powder is a solid supplement. It is designed to be mixed with a liquid, such as water or milk, to create a high-protein drink.

Soy milk is generally the plant-based milk with the highest protein content, often comparable to cow's milk at 7-10 grams per cup.

Yes, protein-rich liquids can help with weight loss by increasing feelings of fullness and boosting your metabolism, which can help reduce overall calorie intake.

Yes, high-quality bone broth typically contains 8-10 grams of protein per cup. The protein is primarily from collagen extracted from the bones during simmering.

Whey protein is absorbed quickly by the body, making it ideal for immediate muscle recovery after a workout. Casein is a slow-digesting protein that provides a sustained release of amino acids, which is beneficial for prolonged periods between meals or overnight.

For cow's milk, the protein content is similar across whole, skim, and low-fat varieties, averaging around 8 grams per cup. The main difference lies in the fat and calorie content.

Absolutely. You can easily increase a smoothie's protein content by adding protein powder, Greek yogurt, or protein-rich additions like nut butters, seeds, and silken tofu.