SKU: 46479641874

OTR-AC (MK-29, OSTARINE-O-ACETATE) Solution, 750mg (25mg/mL)

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Description

OTR-AC (MK-29, OSTARINE-O-ACETATE) Solution, 750mg (25mg/mL)OTR AC (MK 29, OSTARINE O ACETATE) OTR AC, also known as MK 2866 Ester, is MK 2866 (Ostarine) that has undergone esterification (the process of combining an organic acid with an alcohol). This chemical process is used to maximize potency and extend the half life (the time required for a quantity to reduce to half of its initial value) of a substance. Due to this process, the ester version of ostarine has the capacity to remain bioactive ten times

OTR-AC (MK-29, OSTARINE-O-ACETATE)

OTR-AC, also known as MK-2866 Ester, is MK-2866 (Ostarine) that has undergone esterification (the process of combining an organic acid with an alcohol). This chemical process is used to maximize potency and extend the half-life (the time required for a quantity to reduce to half of its initial value) of a substance. Due to this process, the ester version of ostarine has the capacity to remain bioactive ten times longer. This results in benefits such as reduced dosing frequency and more stable blood levels.

How OTR-AC Works 
As the ester version of the selective androgen receptor modulator (SARM) ostarine, OTR-AC is more potent and has longer-lasting effects. By binding to proteins in the body known as androgen receptors, it stimulates the formation of muscle tissue. This, in turn, leads to an increase in muscle mass and strength.

Research on OTR-AC
Increase in Muscle Mass and Strength 
Studies suggest that OTR-AC, along with other SARMs, increases muscle mass and strength by stimulating the formation of muscle tissue:

  • In adult rats, the administration of SARMs, including OTR-AC, resulted in an increase in lean muscle mass and a decrease in body fat percentage.
  • In older male and female rats, OTR-AC administration resulted in increased lean muscle mass, decreased fat mass, and significant improvements in their ability to climb stairs.
  • Studies showed that OTR-AC may help increase muscle mass in rats with cancer cachexia (muscle wasting).
  • In older male and female rats, OTR-AC significantly improved total lean body mass and physical function.
  • In rats that had their ovaries surgically removed, OTR-AC improved muscle tissue.
  • In rats, OTR-AC increased muscle mass by enhancing the production of muscle cells.

Reduction of Body Fat 
Aside from helping gain muscle mass, OTR-AC has also been found to reduce overall body fat:

  • In Phase I and II clinical trials, OTR-AC has demonstrated promising results in increasing total lean body mass, decreasing total tissue fat percentage, and enhancing functional performance.
  • A review of studies showed that OTR-AC can help increase lean body mass and reduce body fat in overweight rats.
  • In a phase 2a study, the administration of OTR-AC along with other SARMs resulted in increased lean fat mass and decreased body fat percentage.
  • In male rats, OTR-AC increased fat cell breakdown by improving lipid metabolism and affecting the release of adiponectin (a hormone that regulates fatty acid breakdown).

Improvement of Bone Health 
Studies suggest that OTR-AC can help stimulate bone formation and protect against bone disorders:

  • In rats that had their ovaries surgically removed, OTR-AC administration resulted in improved bone healing.
  • In a rat model for aged male osteoporosis, both OTR-AC and testosterone treatments improved bone healing by increasing callus volume and area, bone volume and density, and bone width.
  • In a rat model of postmenopausal osteoporosis, high doses of OTR-AC for 5 weeks resulted in increased bone volume, density, and bone mineral density.

 

Reduction of Cholesterol Levels 
Evidence suggests that OTR-AC can help lower cholesterol levels, especially low-density lipoprotein (bad cholesterol):

  • In older male and female rats, OTR-AC administration resulted in a significant reduction in low-density lipoprotein levels.
  • In rats that had their ovaries surgically removed, OTR-AC treatment reduced blood cholesterol levels.

 

Concentration
25mg/ml.

Half Life
24 hours.

DISCLAIMER
This material is sold for use in laboratory research only. Terms of sale apply. Not for human consumption, nor for medical, veterinary use. Please use with our DISCLAIMER before ordering.

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SKU: 46479641874

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4.6 ★★★★★
Based on 25 reviews
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Product Reviews
C
Verified Purchase
cam
Charlottesville, US
★★★★★ 3
Not Chuck-It Durable
Color: Orange & Blue Squirrel, Size: 4.7 inches (1 Pack), Color: Orange & Blue Squirrel, Size: 4.7 inches (1 Pack)
Sadly only lasted an hour. My dog likes to pull apart toys over the course of a few months, with the exception of Chuck-It toys. They usually never get destroyed by him. I think its a good product but if you are looking for the durability like other toys from Chuck It - just wanted to share this is not the toy for you! Made him happy so not regretful of buying it, just wish it lasted longer. Here is him posing with it after he took bites of it like it was an apple.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 24, 2026
L
Verified Purchase
Lance Boudreaux
Alexandria, US
★★★★★ 5
Nice indoor toy
Color: Orange & Blue Roller, Size: 7.5 inches (1 Pack)
Great indoor dog toy. Just pick it up after use if your dog is a chewer like mine is.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 18, 2026
A
Verified Purchase
Amazon Customer
Chelsea, US
★★★★★ 1
1st one lasted over 3yrs, 2nd started falling apart in less than a week....
Color: Orange & Blue Roller, Size: 7.5 inches (1 Pack), Color: Orange & Blue Roller, Size: 7.5 inches (1 Pack)
My dog really loves this toy. He’s a 5yr old border collie. He doesn’t work at tearing up his toys but he does shake his toys. I bought his 1st Chuckit it indoor football over 3yrs ago. It held up very well and had normal wear and tear I’d expect from a chuckit toy to have. It developed a small tear in fabric about 6months ago. As it was still mainly intact, I let him continue to play with it. Then the tear widened and I felt good time to replace, so I ordered one from Amazon. He was ecstatic to have a new one. I was quite disappointed though as in under a week from giving it to him(he’s always supervised during play so I do know what he does with his toys and he doesn’t work at them to tear them up) I noticed a tear down the seam that was bigger than the other one had for 6months. Over the next few days, tear widened. Now cover is completely off of inside. I’m really disappointed in the quality. I’m not sure if the quality of the toy is less than when I got his first one(which I bought in a pet store such as petsmart) or if for some reason because I purchased on amazon, they are of lesser quality. I do know for a fact as I supervise his play and with his favorite toys(and usually his spendier toys) they get put up when it’s not play time. He has his other toys that he can play with anytime. I have ran also into Kong toys (Wubba) that has come apart quickly in under a month,but those were both bought on amazon and at a retail store, so I don’t know if amazon is distributing toys of lesssr quality or if toy brands that have held up in past (Kong Wubba & this Chuckit football) are just being made of lesser quality. My dog’s style of play hasn’t changed nor has his supervision. That being said, my dog absolutely LOVES this toy. I want other users to be forewarned that I’ve had 2 of this product for my dog, they both developed a tear down seam, that eventually led to outer fabric shell coming off of the inner part of the toy. Yes my dog does shake his toys but 1st lasted over 3yrs, 2nd lasted less than a month and is in worse condition than the first. I may purchase this toy again as it’s one of his favorites just to see if the 2nd one was a fluke. Had I paid more than $6.19(I’m a prime member and it was an add on product) I most likely wouldn’t purchase a third one. I’m willing to see if the third one will last at least a yr. if it starts coming apart in less than a week again, I’ll have my answer which would be that chuckit has resorted to making their toys of lessor quality. I hope that’s not the case because they are one of only a couple of brands I hold in high regard for their good quality and durable dog toys. Please see picture. It’s his toy in less than a month. The outer material came off during play last night. It lasted less than a month from time I gave it to him to play with. 5/22/18 update. I bought him a 3rd indoor fumblr, it last almost 3 months...I ordered him a 4th one. I gave it to him Friday, today is Tuesday, his 4th one is already coming apart at the seams. When I ordered 4th fumblr, I bought 2 at the same time, they were $5.19 each(prime member add on price). I’m glad I did because now they are twice the price at now over $10. I very highly doubt I will buy another indoor fumblr unless price drops in half again. This last one that I gave him 4-5days ago, it hasn’t been his daily favorite toy. He’s maybe played with it a couple hrs each day. My dog really LOVES this toy. I’m moving my rating down to a 1 Star from 2 as this toy has consistently come apart rather quickly. I’m very disappointed in the quality of this toy. He’s 5 1/2yrs Old now. 1st fumblr last over 3yrs, he’s gone through the other 3 in under 6months...had I paid over $10 each time, I probably would’ve stopped after the 3rd fumblr came apart. as it is now, I won’t but any more fumblrs by chuckit at this price....if price drops, after he’s gone through the 5th one I have put up...I may consider it...but not at over $10 for a toy that comes apart through normal play in under 5 days...
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Reviewed in the United States on November 4, 2017
B
Verified Purchase
Brooklyn
Natrona Heights, US
★★★★★ 5
Dogs favorite toy
Color: Orange & Blue Roller, Size: 7.5 inches (1 Pack), Color: Orange & Blue Roller, Size: 7.5 inches (1 Pack)
I buy 4 of these every month for my dog. He won’t go anywhere without this ball. He sleeps with it, swims with it, goes to the vet and carries it around in his mouth to show off. It’s borderline a problem. My dog is a large breed and plays hard so I do purchase often because the strings unravel and the ball itself is foam so breaks down into little pieces after a few days of playing. I love that it is fragile on his teeth and jaw. We can play catch indoors because it is soft.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 24, 2026
N
Verified Purchase
NATTY
Battle Creek, US
★★★★★ 5
Love It!
Color: Orange & Blue Fetch Ball, Size: 4.75 inches (1 Pack)
Perfect for your dog who loves to play ball indoors. It doesn’t bounce & it’s very soft. It lasted a long time for a German Shepherd who loveeess to ball all day.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 10, 2026

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