Merck Insulin Syringes U-40 29 Gauge x 0.5-in

Prescription Item

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    $45.49 FREE Shipping over $49

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Count: 100 syringes
Size: 1 mL
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Help deliver your pet’s insulin with ease by using Merck’s U-40 Insulin Syringes. Each box comes with 100 needles that are designed to be used with Vetsulin (porcine insulin zinc suspension) 10 ml. or 2.7 ml. These single-use devices are designed for both canine companions and feline friends and are completely sterile, nonpyrogenic and non-toxic. Choose between a 0.5 mL-29 G x 1/2-inch fixed needle or a 1 mL- 29 G x 1/2 -inch fixed needle.

Proudly sourced directly from the manufacturer or their approved distributor. Guaranteed genuine and backed by the manufacturer.


Vetsulin U-40 Insulin syringes are disposable syringes used to administer Vetsulin to your pet.


Vetsulin should not be used in dogs or cats known to have a systemic allergy to pork or pork products. Vetsulin is contraindicated during periods of hypoglycemia. Keep out of reach of children. As with all insulin products, careful patient monitoring for hypoglycemia and hyperglycemia is essential to attain and maintain adequate glycemic control and prevent associated complications. Overdosage can result in profound hypoglycemia and death. The safety and effectiveness of Vetsulin in puppies and kittens, breeding, pregnant, and lactating dogs and cats has not been evaluated. See the package insert for full information regarding contraindications, warnings, and precautions

This item is excluded from the first-time Autoship promotion.

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  • Item Number
  • For Use With
    Dogs & Cats
  • Common Brand Name(s)
  • Generic Name
    Insulin Syringes
  • Administration Form
  • Lifestage
  • Product Form
  • Health Condition
  • Drug Type
    Devices & Supplies
Recommended Dosage

Use according to your veterinarian's instructions.

Storage Instructions

Syringes should be kept out of the reach of children and pets.


How are doses measured?

Doses of insulin are measured in units: 40 IU/mL insulin contains 40 International Units (IU) per milliliter (mL) (1 mL = 1 cc).

How do I prepare the dose?

After washing your hands, take the Vetsulin (porcine insulin zinc suspension) vial out of the refrigerator. Shake the vial until the insulin is uniformly milky, allowing any foam to disperse.

  1. Carefully remove the cap from the needle and insert the needle into the vial.
  2. Turn the vial upside down, making sure the tip of the needle remains in the vial.
  3. Withdraw the correct dose into the U-40 insulin syringe.
  4. Before removing the needle from the vial, check the syringe for any air bubbles.
  5. If bubbles are present, hold the syringe up and tap its side until the bubbles float to the top. Push them out with the plunger and withdraw the correct dose.
  6. Remove the needle from the vial.

How should I inject my pet?

  1. Injection should be given under the skin, 3/4 to 2 inches from the middle of your cat's back, varying from behind the shoulder blades to the middle of the back region and alternating sides.
  2. Gently insert needle in center of folded skin.
  3. Push plunger until all of the insulin is given.
  4. Pull needle out and dispose of syringe into appropriate sharps collector.
  • Injection point can depend upon your veterinarian's recommendation and what is best for you and your cat.

  • Alternate injection site between left and right side for comfort and best results. Repeat injections at the same site can lead to ineffective treatment.

  • If only a partial dose is given, do not attempt to re-dose. Wait and give your cat its usual dose at the next injection time.

Rating: 3.3 of 5 stars 14 Reviews 14 Reviews 3.4 out of 5 Stars

71% Recommend

71% of reviewersrecommend this product

Rating: 3.3 of 5 stars 3.4 / 5

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14 Reviews

Showing 1-10 of 14 Reviews

  • 1 out of 5 stars

    Terrible quality

    By WMRMOM on Sep 29, 2021

    Syringes leak horribly. Insulin leaks out onto fur before needle can be inserted. Plunger is awful!! Waste of money but can’t be used to inject insulin properly. What a shameful useless product

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  • 5 out of 5 stars

    Quick Delivery

    By Precious on Oct 18, 2021

    This order came quickly and I thought the price was very reasonable. Will order them again for my diabetic senior dog.

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  • 5 out of 5 stars

    Gotta have purchase

    By Debbie on Jun 16, 2021

    I chose to order from Chewy for my sweet girl's insulin injection syringes as our vet's pricing was horrendous. These syringes are quality for sure, but they are individually wrapped; I would rather save a bit of money and get them in bulk packaging. As for the syringe itself, it took me several times to master this particular syringe as it 'leaked' during injection and more went on my dog than in my dog. I have conquered this needle and will most likely order these again, but again ~ individually wrapped might be important for a vet's office but for home use ~ bulk is better.

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  • 2 out of 5 stars

    Flimsy plunger

    By Caretaker on Apr 4, 2021

    Once you measure the insulin, when the needle is pulled from the vial, the plunger can move from that position. You can move the plunger back and forth within the barrel easily with your finger.

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  • 2 out of 5 stars

    Flimsy needles

    By Catservant on Jan 19, 2021

    I recently received insulin and needles for my cat, while the insulin is fine it was shipped with two cold packs promptly, the needles are less than ideal. Even with a larger amount of air (drawn into the needle to combat continued sucking action) the needle keeps wanting to slide/ pulling more insulin while removing it from the vile. I have found this annoying as holding the end of the syringe seems to push some back into the vile, so you either get more air or less insulin than desired.These needles seem flimsy, I was more happy with my last batch. I'm certain this is nothing on Chewy's end as they have always been satisfactory in every order I've given them-

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  • 5 out of 5 stars

    superior syringes for my dogs diabetes

    By DiabeticDoggieMama on Apr 29, 2020

    My dog, Wilma, would cry out when we used syringes of lesser quality. The Vetsulin U-40 syringes are more expensive but worth the extra money not having her cry out in pain when we have to inject her with Vetsulin twice a day. Wilma was an older doxie mix we adopted from our local So CA shelter. She had been found lost and wandering in the lower desert area. She became sick about a year after we adopted her and barely survived diabetic Keto Acidosis.

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  • 5 out of 5 stars

    Exactly what I needed

    By Annette on Oct 31, 2020

    Was authorized by prescription very quickly. Thank you!

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  • 5 out of 5 stars

    no reason for these to be so expensive

    By Tamara on Apr 10, 2020

    I like the needles. They're fine. BUT, these needles should cost no more than $15.00 for 100 in the cardboard box. Something is amiss here. There are plenty of other places that, even paying shipping, will cost about 1/3 of this price.

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  • 1 out of 5 stars

    diabetic pom owner

    By 1949Linda on Feb 16, 2020

    Why the heck are these syringes now so expensive! Syringe is less handy to use. Where is the plastic box unit where you can put yourvsyringes into? Totally not biting from Chewy these any more!

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  • 2 out of 5 stars

    Merck syringes

    By Charlie on Dec 26, 2019

    New syringe design lacks features of earlier model by same manufacturer. That is: the plunger is smaller and harder to grasp. Also, the red measurement lines are faint and difficult to read.

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