ProZinc Insulin U-40 for Dogs and Cats, slide 1 of 1

ProZinc Insulin U-40 for Dogs and Cats, 10-mL

Prescription Item

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ProZinc is a protamine zinc insulin prescribed by veterinarians to help support the insulin levels of diabetic cats and dogs. It typically effects your pet for 10-14 hours at a time, which helps to keep their blood glucose level consistent throughout the day. It contains recombinant DNA that mimics human insulin, so it helps to control your pet's diabetic symptoms and keeps them comfortable.


For the reduction of hyperglycemia and hyperglycemia-associated clinical signs in cats and dogs with diabetes mellitus.

Possible Side Effects

Pet parents should be advised to observe for signs of hypoglycemia. Use of this product, even at established doses, has been associated with hypoglycemia. An animal with signs of hypoglycemia should be treated immediately. Appropriate diagnostic tests should be performed to rule out other endocrinopathies in diabetic cats that are difficult to regulate.

Drug & Food Interactions

Talk to your veterinarian about any other drugs your cat or dog is taking before starting this medication.


Animals presenting with severe ketoacidosis, anorexia, lethargy, and/or vomiting should be stabilized with short-acting insulin and appropriate supportive therapy until their condition is stabilized. As with all insulin products, careful pet monitoring for hypoglycemia and hyperglycemia are essential to attain and maintain adequate glycemic control and to prevent associated complications. Overdosage can result in profound hypoglycemia and death. Progestogens, certain endocrinopathies and glucocorticoids can have an antagonistic effect on insulin activity. Progestogen and glucocorticoid use should be avoided.


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  1. Prescribing Information

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  • Item Number
  • Common Brand Name(s)
  • Generic Name
    Protamine Zinc Recombinant Human Insulin
  • For Use With
    Dogs & Cats
  • Administration Form
  • Brand
    Boehringer Ingelheim
  • Product Form
  • Health Condition
  • Drug Type
    Insulin, Hormone

Insulin, Protamine Sulfate, Zinc Oxide, Glycerin, Dibasic Sodium Phosphate, Heptahydrate Phenol (added as a preservative), Hydrochloric Acid. Water for Injection (maximum).

Recommended Dosage

See prescribing information for recommended dosage for your pet.

Storage Instructions

Store in an upright position under refrigeration at 36° - 46°F. Do not freeze. Protect from light.


What is Prozinc?

Prozinc is an aqueous protamine zinc suspension of recombinant human insulin that is used to reduce high blood sugar (hyperglycemia) in dogs or cats with diabetes mellitus. A veterinarian must prescribe Prozinc for your dog or cat. Prozinc should be given only to the dog or cat for which it is prescribed. Keep out of reach of children. Seek medical attention immediately if you accidentally inject yourself with Prozinc.

What is diabetes mellitus?

Diabetes mellitus occurs when a dog or cat has insufficient levels of, or an abnormal response to, insulin. The low insulin levels may result in high blood glucose that could produce the following changes in your dog or cat:

  • Increased thirst.
  • Increased urination.
  • Increased appetite .
  • Weight loss.
  • High levels of glucose in the urine (glycosuria).
  • Weakness in the back legs.

What kind of results can I expect when my dog or cat is on ProZinc insulin for diabetes mellitus?

Although ProZinc insulin is not a cure for diabetes mellitus, it can help reduce the levels of glucose in the blood, which can help alleviate the clinical signs.

What should I discuss with my veterinarian before giving ProZinc insulin?

Talk to your veterinarian about:

  • The signs of diabetes mellitus you have observed (for example, increased thirst and urination).
  • The importance of proper insulin storage, handling, and administration techniques (for example, how to gently roll the vial prior to each use, the proper appearance of the product after mixing, how to fill the U-40 syringe with the proper amount of insulin, and where and how to inject the insulin).
  • The importance of maintaining the dog or cat under the same conditions for diet, exercise, environment, etc.
  • The importance of follow-up visits for testing to determine if dose adjustments of ProZinc insulin are necessary. Tell your veterinarian about:
  • Any side effects your dog or cat has had when receiving other insulin products.
  • Any medical problems or allergies that your dog or cat has now or has had in the past.
  • All medications that you are giving your dog or cat or plan to give your dog or cat, including those you can get without a prescription.
  • If your dog or cat is pregnant, nursing, or if you plan to breed your dog or cat.

What are the possible side effects that may occur in my dog or cat during ProZinc therapy?

ProZinc insulin, like other drugs, may cause some side effects. Serious side effects can occur with or without warning. Please contact your veterinarian immediately if you think your dog or cat has a medical problem or side effect of ProZinc therapy. The most common insulin-related side effect is low blood glucose (hypoglycemia). Signs of hypoglycemia may occur suddenly and can include:

  • Weakness.
  • Depression, lethargy, sluggishness.
  • Staggering gait.
  • Behavioral changes.
  • Muscle twitching.
  • Seizures.
  • Coma.
  • Death.

What actions do I take if my dog or cat shows signs of hypoglycemia?

  • If your dog or cat is unconscious or having a seizure, this is a medical emergency. Take your dog or cat to the veterinarian immediately.
  • If your dog or cat is conscious, rub approximately 1 tablespoon of corn syrup or honey on your cat’s gums. When it is able to swallow, give corn syrup or honey by mouth until your dog or cat is alert enough to eat. Feed the usual meal and contact your veterinarian.

When should my dog or cat not be given ProZinc insulin?

Do not give your dog or cat its prescribed dose of ProZinc insulin if it:

  • Is experiencing an episode of low blood glucose (hypoglycemia). Common causes for hypoglycemia include excessive doses of insulin, failure to eat, strenuous exercise, changes in the body’s need for insulin, diabetes-inducing disease or drug effects.
  • Is not eating or is vomiting.
  • Is sensitive to protamine zinc recombinant human insulin or any other ingredients in ProZinc product.
  • Do not give your dog or cat its prescribed dose of ProZinc insulin if you see clumps or visible white particles in the vial after gently rolling.

How should I give ProZinc insulin to my dog or cat?

Give ProZinc insulin with U-40 syringes only. Use of a syringe other than a U-40 syringe will result in incorrect dosing. Gently roll the vial until the ProZinc has a uniformly cloudy, white appearance. If there are clumps or visible white particles in the vial after gently rolling, do not use the ProZinc and you’re your veterinarian. ProZinc insulin should be given according to your veterinarian’s instructions. Your veterinarian will tell you what amount of ProZinc insulin is right for your dog or cat and instruct you on techniques for administration.

Can ProZinc insulin be given with other medications?

ProZinc insulin can be given with other medications, but the dose may need to be adjusted due to the medication resulting in either increased or decreased insulin requirements. Tell your veterinarian about all medications you have given your cat in the past, and any medications that you are planning to give with ProZinc insulin. This should include medications that you can get without a prescription. Your veterinarian may want to ensure that all of your dog or cat’s medications can be given together.

What should I do if I inject more than the prescribed amount of ProZinc insulin?

Contact your veterinarian immediately and, if your veterinarian is not available, seek other veterinary advice at once.

What should I do if my dog or cat receives less than the prescribed dose, or I miss an injection?

  • Contact your veterinarian as soon as possible for advice on your dog or cat’s next dose.
  • If you cannot reach your veterinarian and your dog or cat is eating and acting normally, give your cat the usual dose at the next regularly scheduled injection time.

How should I store ProZinc insulin?

ProZinc insulin should be stored in an upright position under refrigeration at 36 - 46°F (2 - 8°C). Do not freeze. Protect from light.

What else should I know about ProZinc insulin?

If you have any questions or concerns about the product or diabetes mellitus, talk to your veterinarian. As with all prescribed medications, ProZinc insulin should only be given to the dog or cat for which it is prescribed and for the condition for which it was prescribed. It is important to periodically discuss your dog or cat’s response to ProZinc insulin at regular checkups that may include blood glucose monitoring. Your veterinarian will best determine if your dog or cat is responding as expected and should continue receiving ProZinc insulin.

What is the best number to call regarding any specific product questions?

For any specific product questions, please call Boehringer Ingelheim Animal Health’s customer service line number at 1-888-637-4251.

Rating: 4.7 of 5 stars 106 Reviews 106 Reviews 4.8 out of 5 Stars

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98% Recommend

98% of reviewersrecommend this product

Rating: 4.7 of 5 stars 4.8 / 5

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106 Reviews

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  • 5 out of 5 stars

    ProZinc for cats

    By on

    A lifesaving drug at a reasonable price. Since it is temperature sensitive, fast and appropriate shipping is essential. My order, the first from Chewy Pharmacy, came in a styrofoam box in which 2 ice packs were placed in the bottom, then the product in a plastic bag, topped by a thin layer of bubble wrap. Why wasn't the product placed in between 2 ice packs? In the extreme heat, the ice packs were beginning to melt (presumably while on the delivery truck). The product arrived still cool, but it could easily have been otherwise! Better packaging needed!!!

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  • 5 out of 5 stars

    Beats the competition!

    By on

    This item is required to be shipped in a cold pack cooler. I ordered this from Chewy because their is no additional fee , unlike your competitor, to ship the insulin in a cold pack. The insulin price is the same in both places.

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  • 5 out of 5 stars

    Ships well!

    By on

    Same insulin I have bought from our vet for 4.5 years, at a (slightly) lower cost - but in these uncertain times Chewy auto ship is a lifesaver - I won't be worried about running low and if the vet has it in stock or can order it for me within the week. I was very concerned about the shipment element as its summer in Texas but it was packed very well and still perfectly chilled when it arrived at my door.

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  • 5 out of 5 stars

    So impressed

    By on

    I was nervous that the insulin may get warm in the travels, but it came sealed tight in a foam cooler with ice packs! Still cold! I was really impressed!

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  • 5 out of 5 stars

    Great, no issues

    By on

    The insulin arrived quickly and was packed well. No issues with the shipping company when it came to receiving my cat’s medication.

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  • 5 out of 5 stars

    perfect shipment

    By on

    Chewy has the best price around for ProZinc insulin. It was well-packed in a styrofoam chest and cold packs and very speedy shipping.

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  • 5 out of 5 stars

    Timely delivery

    By on

    It looks like about 24 hours in transit, but the kitty insulin arrived well-packed, with ice packs still frozen!

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  • 5 out of 5 stars

    Easy procedure for prescription med

    By on

    I was very pleased with the Chewy pharmacy in getting this prescription med set up. Now I can count on having the med and the needles every month.

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  • 5 out of 5 stars

    Prozinc works

    By on

    My cat has been diabetic for a few years and this is the insulin that has been our savings Grace I love that it is so much cheaper than the vet and chewy ships for free I am excited I can get her diabetic food there now too I realize that times are hard now with the covid 19 but we need to have more patience and realize that chewy was doing there best under hard circumstances and over whelming orders just order your products ahead before you need them thank you chewy and all your essential workers

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  • 5 out of 5 stars

    you guys are the best!

    By on

    I am always so pleased by Chewy you really care for everyones pets. The insulin was packed well and was cold in this heat . Thank you

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