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Magnesium Protein Complex

(Mg-Plus Protein)

  • Español PDF

Magnesium Protein Complex is a medicine that contains magnesium salt. It is used to treat and prevent low magnesium level (hypomagnesemia).

What is Magnesium Protein Complex?

Magnesium Protein Complex (also called Mg-plus Protein) is a medicine that contains magnesium salt. This type of medicine is known as an electrolyte supplement, which is used to add extra minerals to your body. Magnesium Protein Complex is used to add the mineral magnesium in your daily diet to treat and prevent low magnesium levels (hypomagnesemia).

Is it safe for my child to take this medicine?

Yes, it is safe to take this medicine as directed if your child’s healthcare provider has prescribed it, unless any of these reasons not to take it apply to your child: 

  • Do not use if your child has an allergy to Magnesium Protein Complex or any other part of this medicine. Tell your child’s healthcare provider or pharmacist if they are allergic to any medicines, food preservatives or dyes. This medicine contains a small amount of soy protein. If your child has an allergy to soy, please check with your healthcare provider to see if it is still OK to give this medicine to your child.
  • Do not use if your child has a slow heartbeat without a working pacemaker, or serious kidney disease.

Where do I get Magnesium Protein Complex?

You can fill your child’s prescription for Magnesium Protein Complex at any Seattle Children’s Pharmacy location. Information on hours and directions can be found at seattlechildrens.org/clinics/pharmacy.

You can also order it directly from MG Plus Protein company:
1-800-323-2935 or mgplusprotein.com.

How do I give Magnesium Protein Complex to my child?

  • This medicine comes in a tablet form. Your child’s healthcare provider will tell you how to give the medicine and how often.
  • Stay well hydrated while taking this medicine. Your child should drink at least 6 to 8 cups (about 8 ounces each) of liquid each day, unless your doctor tells you otherwise.
  • It is OK to crush the tablet for oral administration. Magnesium Protein Complex can not be given through a feeding tube.
  • Ask your child’s healthcare provider or pharmacist for additional information on how to give the tablet form of Magnesium Protein Complex.

What do I do if my child misses a dose?

  • Do not give your child an extra dose or 2 doses at the same time.
  • Give the missed dose as soon as possible. If it is near the time when the next dose is due, wait to give your child the medicine on the regular schedule. Skip the missed dose.
  • Call your child’s healthcare provider if you have any questions about whether or not to give a dose of medicine.

How do I store this medicine?

  • Keep all medicine away from children and pets.
  • Never share your medicine with anyone.
  • Store the medicine at room temperature in a tightly closed container, away from heat, moisture and direct light.

How do I dispose of this medicine?

Visit the FDA (Food and Drug Administration) website fda.gov, or takebackyourmeds.org for a list of pharmacies that take back unwanted medicines for disposal.

If no take-back program is available in your area, throw the drugs in the household trash, but first:

  • Take them out of their original containers and mix them with an undesirable substance, such as used coffee grounds or kitty litter.
  • Put them in a sealable bag, empty can, or other container to prevent the medication from leaking or breaking out of a garbage bag. 

For more information about how to dispose of medicine, refer to the Seattle Children’s flyer called “How to Get Rid of Unused Prescription Drugs: Guide to Proper Disposal” (seattlechildrens.org/pdf/PE784.pdf).

How do I keep my child safe while taking this medicine?

  • Check with your child’s healthcare provider to make sure your child’s other medicines can be taken with Magnesium Protein Complex.
  • Check with your child’s healthcare provider if your child has kidney disease, myasthenia gravis, or nerve disease.
  • Check with your child’s healthcare provider if your child has a device for the heart, such as a pacemaker.

What are some possible side effects of this medicine?

  • Mild diarrhea
  • Nausea
  • Stomach pain

When should I call my child's healthcare provider?

You should call your child’s healthcare provider if they have any of these signs or symptoms:

  • Skin rash, hives
  • Sore throat or fever
  • Joint pain
  • Tingling, pain or weakness in hands or feet
  • Call your child’s healthcare provider if they do not get better in a few days or if the symptoms worsen.
  • Call your child’s healthcare provider and dial 911 right away if your child has trouble breathing, fever, itching, blue skin color, bad cough, or swelling of the face, lips, throat or tongue.
  • Call local poison control center or dial 911 if you believe your child has taken a large amount of this medicine.

Source: 

Magnesium. Drug Note. Thomson Micromedex.
www.micromedexsolutions.com. Accessed October 7, 2014.

To Learn More

  • Ocean Pharmacy
    206-987-2138
  • Ask your child’s healthcare provider
  • seattlechildrens.org/patient-education

Free Interpreter Services

  • In the hospital, ask your nurse.
  • From outside the hospital, call the toll-free Family Interpreting Line, 1-866-583-1527. Tell the interpreter the name or extension you need.
Seattle Children's Hospital

Seattle Children’s offers free interpreter services for patients, family members and legal representatives who are deaf or hard of hearing or speak a language other than English. Seattle Children’s will make this information available in alternate formats upon request. Call the Family Resource Center at 206-987-2201. This handout has been reviewed by clinical staff at Seattle Children’s. However, your needs are unique. Before you act or rely upon this information, please talk with your healthcare provider.

© 2026 Seattle Children’s, Seattle, Washington. All rights reserved.

02/01/2025
PE2055
Patient and Family Education | Pharmacy

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