Does Casein Protein Cause Hair Loss

Based on our research of existing studies, casein protein does not directly correlate to hair loss. In fact, you should just avoid whey protein isolate in some protein shakes and keep drinking whey protein if you have protein-deficient, e.g due to workout, to promote hair growth.

In a 2010 study published in the Journal of Strength and Conditioning Research, scientists discovered high levels of branched-chain amino acids (BCAAs)in whey protein isolate (WPI) were the prime culprit to increased testosterone. 

Scientists believe high levels of testosterone in men can cause baldness, because the hormone acts directly on many of the body’s tissues, including hair follicles. The hormone is then broken down into dehydroxytestosterone (DHT) which is known to cause hair loss and baldness. 

Dr. Bessam Farjo, a hair transplant surgeon, said:

Whey protein exaggerates or accelerates the hair loss process because there is evidence it increases the level of testosterone when combined with muscle-building exercise.

Hair transplant surgeon and dermatologist Dr. Larry Shapiro discovered that a certain type of WPI can aggravate or accelerate hair loss compared to Whey Protein Concentrate (WPC) which helped in hair gain. 

Consumers need to be made aware that taking WPI can damage and accelerate hair loss. Through my research, we've discovered that a vitamin enriched WPC has a very positive effect on healthier, fuller looking hair.

The Truth is Avoid Whey Protein Isolate 

Casein protein, together with whey protein, has often been blamed for being partly responsible for accelerating hair loss in those who consume it on a regular basis. Many experts believe that foods that contain casein and whey protein isolates may be partly responsible for their untimely hair loss.

The two most common forms of whey protein powder are 

  • whey protein concentrate (WPC) 
  • whey protein isolate (WPI). 

They differ in protein, fat, and lactose content. WPC has higher levels of fats and carbohydrates compared to WPI. And with the higher protein content in WPI, there are also higher levels of branch-chain amino acids, or BCAAs, which are essential to muscle protein synthesis. 

Therefore avoiding WPI would seem to resolve the hair loss problem while taking WPC would improve hair growth instead.

The only exception is those with current kidney or liver disease, you need to limit your protein intake. If you take 1-2 scoops of casein per day, then it is highly unlikely that you will get any noticeable side effects, let alone serious ones too. (

On whey protein, read our other post on whey protein and hair loss.

Below we shared more about casein protein for those who do not know

1. The misconception of Casein Protein Being Milk Protein

Many called casein protein as milk protein because the protein percentage in cow's milk is made of 80 percent casein. However, that is a misconception since breast milk is also 20 to 40% casein protein. According to, human milk contains two types of proteins: 60% whey and 40% casein. 

Whey protein is the fluid or liquid part of the milk which when removed leaves the curd or casein that is the solid part.

2. Casein As a Slow-Release Complete Protein

Whey protein is touted as the best kind of protein supplement because it provides high-quality protein and contains all 9 essential amino acids. Similar to whey protein, casein protein is a complete protein containing the 9 essential amino acids.

Essential amino acids are important to your body's needs for growth and repair. In post that casein protein is underrated, it shared that casein contains various unique proteins and bioactive compounds, some of which have health benefits.

Protein is important for hair growth so there is no denying you need protein.

Casein contains a large amount of the amino acid glutamine -- it's actually 20 percent glutamine, one of the 22 different amino acids that form the building blocks of all protein. (

Casein releases protein slower than whey protein based on 2 studies:

  • One study tested digestion speed by providing participants with either a casein or whey protein shake. Researchers monitored the blood amino acid content, specifically the key amino acid leucine, for seven hours after ingestion. Whey protein provided a quicker and larger spike due to its rapid absorption rate. Despite a smaller initial peak, casein levels stayed more consistent over time. 
  • In another study, researchers gave participants either whey or casein protein and then measured their digestion rate by analyzing circulating levels of the amino acid, leucine, over a seven-hour period. They found that circulating levels of leucine rose 25% higher in the whey protein group, indicating faster digestion.

This means that the casein group reduced the total amount of protein burned for fuel over a seven-hour period. That means an improved net protein balance, a key factor for muscle growth and retention.

Dr. Larry Shapiro showed,  consuming WPC supported hair transplant patients' hair growth and hair health.

Efforts have been made to get the information as accurate and updated as possible. If you found any incorrect information with credible source, please send it via the contact us form
Sky Hoon
Hair Lover, Idea Starter. He started HairQueenie, which is ranked #27 in the FeedSpot Top 40 Hair Care Blogs and mentions in ManeAddicts and Tempest. Hair is not everything but something. He started Hairqueenie to share great hair products. Over time, he found there are more value to share answers to hair problems that cannot be found easily.
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