Safety
Mighty K9 Side Effects: What to Watch For and When to Call the Vet
The most likely Mighty K9 side effects come from the oil: loose stool, vomiting and slow weight gain, since each 2 mL serving is 16.2 kcal of fat. Dogs with a pancreatitis history or on a low-fat diet need a vet's okay first. No one has studied long-term C60 safety in dogs. If your dog drinks the bottle, call your vet or ASPCA Poison Control.
Written by the Mighty K9 editorial teamUpdated
What to watch
What are the side effects of Mighty K9?
Most possible side effects come from adding fat to the bowl.
| Sign | Likely reason | What to do |
|---|---|---|
| Loose or greasy stool | Extra oil the gut is not used to | Pause and ask your vet before restarting |
| Vomiting once | Fat on an empty or sensitive stomach | Stop and give it only with a full meal |
| Slow weight gain | 16.2 kcal a day adds up | Trim treats; weigh monthly |
| Itching or ear flare | Possible food reaction; flavor source unlisted | Stop and ask your vet |
| Repeated vomiting, belly pain, no appetite | Possible pancreatitis (Merck Vet Manual, Pancreatitis (owner)) | Stop and call your vet the same day |
The label serving is 2 mL a day, given with food. Do not give more to catch up on a missed day. See how to use it for measuring tips.
Calories
Can Mighty K9 make my dog gain weight?
Yes, if nothing else changes. One serving adds 16.2 kcal of fat, and small dogs feel that most.
Extra weight is hard on sore joints. Losing about 6% of body weight cut lameness in obese dogs with arthritis (Marshall et al., 2010). Give one fewer small treat on oil days, and weigh your dog every month.
Fat and the pancreas
Is Mighty K9 safe for dogs prone to pancreatitis?
Ask your vet first. Fatty food and large amounts of table scraps are a common suspected trigger for pancreatitis, and dogs recovering from it go on low-fat diets (Merck Vet Manual, Pancreatitis (owner)).
For a dog with a pancreatitis history, high triglycerides or a prescribed low-fat food, any added fat is your vet's call.
Repeated vomiting, a hunched or painful belly, refusing food, weakness or diarrhea. Stop the oil and call your clinic.
ESS60
Is C60 safe for dogs long term?
Nobody knows. There are no long-term safety studies of C60 or ESS60 in dogs. The few studies that exist were short, small or done in other animals.
- 14 days in rats. A study at 3.8 mg/kg a day found no harm. SES Research, the ESS60 owner, funded it, and two authors co-own the company (Burres et al., 2024).
- Light breaks it down. In a 2021 mouse study, C60 in olive oil broke down under light, and those samples made mice ill (Grohn et al., 2021).
- Inhaled C60 is different. Government studies of breathed-in C60 found lung changes in rats and mice. That does not show what swallowed C60 does (National Toxicology Program, 2020).
- Dogs. The only dog report fed 6 beagles another C60 oil for 9 days (Hui et al., 2023).
So keep the cap tight and the bottle in a cool, dark cupboard. If the oil looks or smells off, stop and call the order desk. More detail is on the ESS60 ingredient page.
Accidents
What if my dog drinks a whole bottle of Mighty K9?
The label says: "In case of accidental overdose, contact a health professional immediately." For a dog, that means your vet or a pet poison line.
Check what is left
Estimate how much is gone. A full bottle is 60 mL, about 486 kcal of fat.
Call for advice
Call your vet or ASPCA Animal Poison Control at (888) 426-4435, open 24/7; a fee may apply (ASPCA Animal Poison Control).
Watch 48 hours
Look for vomiting, diarrhea, belly pain or refusing food. Do not make your dog vomit unless told to.
Try Mighty K9 for 30 days2 mL a day · from $64.99 a bottle · free U.S. shipping on 3+ bottles
Order nowFit check
Who should skip Mighty K9 or ask a vet first?
Answer five quick questions. Any "yes" means a talk with your vet before the first serving.
Mighty K9 is a supplement for dogs, not a veterinary drug. Ask your vet first if your dog has had pancreatitis, is on a low-fat or weight-loss diet, takes any medicine (including pain relievers), is under six months old, or is pregnant or nursing. Limping or crying out needs an exam, not a supplement. See side effects and safety.
Pregnant or nursing dogs have no safety data at all, so wait for your vet's advice. Read who Mighty K9 is for for the full list.
Report it
How do I report a side effect from Mighty K9?
Tell your vet first, then file a report. Reports help regulators spot problems with animal supplements.
| Who | How | Use it for |
|---|---|---|
| FDA, Form 1932a | Email [email protected]; questions 1-888-FDA-VETS (FDA, Report Animal Drug Side Effects) | Side effects from animal supplements |
| FDA Safety Reporting Portal | safetyreporting.fda.gov (FDA, Report a Pet Food Complaint) | Product complaints; keep the lot number and packaging |
| ASPCA Animal Poison Control | (888) 426-4435, 24/7, fee may apply (ASPCA Animal Poison Control) | Accidental overdose or swallowing the bottle |
| Order support | +1 (302) 200-3480 | Batch questions and refunds for orders placed here |
Keep notes: breed, age, weight, start date, amount, what happened, other medicines and the lot code. Other questions go through the contact page.
Medicines
Can I give Mighty K9 with Rimadyl or other NSAIDs?
Ask your vet. No study has tested Mighty K9 with any dog medicine, so nobody can say it is risk-free together. Your vet should know every supplement your dog gets.
Vet NSAIDs are a first-line arthritis treatment, and they have their own side effects. Watch for vomiting, poor appetite, diarrhea and less activity. Serious ones include stomach ulcers and kidney or liver harm (FDA, Pain Relievers for Pets).
Ibuprofen, naproxen, aspirin and acetaminophen can harm dogs. Give none of them unless your vet says so (FDA, Pain Relievers for Pets).
Start one new thing at a time. Our post on supplements versus vet treatment covers the trade-offs.
FAQ
Mighty K9 safety FAQ
What are the most common side effects of Mighty K9?
Loose or greasy stool and an upset stomach are the most likely, because the product is olive oil. Some dogs may vomit if it is given without food. Slow weight gain can follow, since each serving adds 16.2 kcal. Stop and call your vet if vomiting repeats.
Is Mighty K9 safe for dogs?
It has a short label of three ingredients, but its long-term safety in dogs has not been studied. The only formal C60 safety study lasted 14 days in rats and was paid for by SES Research, which two authors co-own (Burres et al., 2024). Healthy adult dogs are the usual users; ask your vet first.
Can Mighty K9 cause diarrhea in dogs?
It can. Any added oil may loosen stool, especially in the first days. Give it with a full meal. If it continues for more than a day or two, or you see blood, stop and call your vet.
Can a dog overdose on Mighty K9?
A whole bottle is 60 mL, about 486 kcal of fat, which can upset the gut and may raise pancreatitis risk in some dogs. The label says to contact a health professional at once. Call your vet or ASPCA Poison Control at (888) 426-4435 (ASPCA Animal Poison Control).
Can dogs with pancreatitis take Mighty K9?
Only with a vet's approval. Each serving is pure fat, and dogs recovering from pancreatitis are usually put on low-fat diets (Merck Vet Manual, Pancreatitis (owner)). Your vet can decide whether 2 mL of oil fits the plan.
Who do I tell if a dog supplement causes a bad reaction?
Call your vet, then report it to the FDA on Form 1932a by email to [email protected], or call 1-888-FDA-VETS (FDA, Report Animal Drug Side Effects). Keep the bottle, box and lot number. For orders placed here, also call +1 (302) 200-3480.
Who wrote this
Written and reviewed by
Plain-language pages built from the label, the sales page and linked veterinary sources.
Last updated . See our editorial standards, and how we check reviews, before you rely on a page. This website is run by a U.S. stocking partner, not by the manufacturer. We are paid when you buy through our order links.
Keep reading
More about Mighty K9
Who it's for
A five-question check, the calorie math by dog size, and the dogs that should see a vet before starting.
Read more
How to use
Two droppers, one meal, every day: measuring, mixing, picky eaters, missed days, travel and dark storage.
Read more
Ingredients
All three Mighty K9 ingredients in label order, with amounts, jobs and what dog research shows.
Read moreU.S. stocking partner for Mighty K9
Ready to try Mighty K9?
Pick a pack. Every bottle holds 30 daily servings, enough to cover the whole 30-day money-back window.
- Secure checkout
- 30-day money-back window
- Ships from the U.S. with tracking