WHEY PROTEIN – Efficacy, Side Effects, Safety and Drug Interactions

Carrageenan Featured in “The GNC Gourmet: The Fun of Multipurpose Ingredients
The 4 Hour Chef – “The Scientist”


Consumer Information and Education
Provided by
Based on
Natural Medicines Comprehensive Database
Natural Medicines Comprehensive Database


What is it?
Whey protein is the protein contained in whey, the watery portion of milk that separates from the curds when making cheese.

Whey protein is used for improving athletic performance, as a food supplement, as an alternative to milk for people with lactose intolerance, for replacing or supplementing milk-based infant formulas, and for reversing weight loss and increasing glutathione (GSH) in people with HIV disease.

Whey protein is also used for protein allergy, asthma, high cholesterol, obesity and weight loss, preventing allergies in infants, late-stage cancer, and colon cancer.

Is it Effective?
Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The effectiveness ratings for WHEY PROTEIN are as follows:

Possibly Effective for…

  • Improving athletic performance. Some clinical research shows that taking whey protein in combination with strength training increases lean body mass, strength, and muscle size.
  • Decreasing weight loss in people with HIV disease (AIDS).
Insufficient Evidence to Rate Effectiveness for…

  • Use as an alternative to milk for people with lactose intolerance. Developing research suggests that infants who are given whey protein during the first 6 months of life have a lower risk of developing allergies (atopic disease) such as milk protein allergy.
  • Late-stage cancer. There is some evidence that taking whey protein might help reduce tumor size in some people with cancer that has spread.
  • Asthma.
  • High cholesterol.
  • Obesity.
  • Other conditions.

More evidence is needed to rate whey protein for these uses.

How does it work?
Whey protein is a source of protein that might improve the nutrient content of the diet. Whey protein might also have effects on the immune system.
Are there safety concerns?
Whey protein is LIKELY SAFE for most adults when used appropriately. High doses can cause some side effects such as increased bowel movements, nausea, thirst, bloating, cramps, reduced appetite, tiredness (fatigue), and headache.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Not enough is known about the use of whey protein during pregnancy and breast-feeding. Stay on the safe side and avoid use.

Milk allergy: If you are allergic to cow’s milk, avoid using whey protein.

Are there any interactions with medications?

Alendronate (Fosamax)

Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.

Whey protein can decrease how much alendronate (Fosamax) the body absorbs. Taking whey protein and alendronate (Fosamax) at the same time can decrease the effectiveness of alendronate (Fosamax). Don’t take whey protein within two hours of taking alendronate (Fosamax).

Antibiotics (Quinolone antibiotics)

Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.

Whey protein might decrease how much antibiotic the body absorbs. Taking whey protein along with some antibiotics might decrease the effectiveness of some antibiotics. To avoid this interaction take whey protein supplements at least one hour after antibiotics.

Some of these antibiotics that might interact with whey protein include ciprofloxacin (Cipro), enoxacin (Penetrex), norfloxacin (Chibroxin, Noroxin), sparfloxacin (Zagam), trovafloxacin (Trovan), and grepafloxacin (Raxar).

Antibiotics (Tetracycline antibiotics)

Interaction Rating = Moderate Be cautious with this combination.
Talk with your health provider.

Whey protein contains calcium. The calcium in whey protein can attach to tetracyclines in the stomach. This decreases the amount of tetracyclines that can be absorbed. Taking calcium with tetracyclines might decrease the effectiveness of tetracyclines. To avoid this interaction, take whey protein two hours before or four hours after taking tetracyclines.

Some tetracyclines include demeclocycline (Declomycin), minocycline (Minocin), and tetracycline (Achromycin).


Interaction Rating = Major Do not take this combination.

Whey protein might decrease how much levodopa the body absorbs. By decreasing how much levodopa the body absorbs, whey protein might decrease the effectiveness of levodopa. Do not take whey protein and levodopa at the same time.

Are there any interactions with Herbs and Supplements?
There are no known interactions with herbs and supplements.
Are there interactions with Foods?
There are no known interactions with foods.
What dose is used?
The following doses have been studied in scientific research:


  • For improving athletic performance: 1.2-1.5 grams/kg of whey protein in combination with strength training for 6-10 weeks.
  • For HIV/AIDS-related weight loss: 8.4-84 grams of whey protein per day, or 2.4 grams/kg per day in a high-calorie formula, or 42-84 grams per day in a glutamine-enriched formula.
What other names is the product known by?
Bovine Whey Protein Concentrate, Concentré de Protéine de Petit-Lait Bovin, Fraction de Lactosérum, Fraction de Petit-Lait, Goat Milk Whey, Goat Whey, Isolat de Protéine de Lactosérum, Isolat de Protéine de Petit-Lait, Lactosérum de Lait de Chèvre, MBP, Milk Protein, Milk Protein Isolate, Mineral Whey Concentrate, Proteínas del Suero de la Leche, Protéine de Lactosérum, Protéine de Lait, Protéine de Petit-Lait, Whey, Whey Fraction, Whey Peptides, Whey Protein Concentrate, Whey Protein Hydrolysate, Whey Protein Isolate.


Whey Protein Isolate (WPI)

{ 5 comments… read them below or add one }

sudha February 16, 2014 at 9:46 am

can we use herbalife whey protein shake for weight loss? does it have any side effects? if we can use it please mention the quantity and preferable timings to take the shake.


Stephen February 17, 2014 at 6:14 pm

You certainly can Sudha, but I personally feel Herbalife is overpriced and overrated. I prefer Vega One http://amzn.to/1jyKyU4. I would use one scoop as a post workout snack.

– Stephen


Thinner1too April 1, 2014 at 6:07 pm

I use pea protein by Now and it is terrible. Do you suggest this. I choke it down when I get up in the AM to get my protein in first thing.



Stephen April 6, 2014 at 7:16 am

No, life is too short to wake up to this every day in my opinion. Find something you enjoy and stick with that. Even the studies show that this will work better in the long run, there are lots of options: http://www.4hourlife.com/2012/11/29/how-to-get-30-grams-of-protein-within-30-minutes-of-waking-up/

– Stephen


sudha February 19, 2014 at 5:55 am

thank you sir


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