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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4.4 ★★★★★
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Pete V
West Palm Beach, US
★★★★★ 5
Perfect fit
Size: 9-9.5, Color: Blue/Grey
I think these shoes are excellent. I ordered a pair which arrived after 2 days. Contrary to some reviews I do not find these water shoes a tight fit at all. And I have bunions. Indeed I find them very comfortable. I have used them in water and as advertised they drain dry pretty quickly. In short I am delighted with the shoes. So much so that I ordered a second pair. Different colour of course. They just arrived and I am wearing them now. Same size and just as comfortable. Thank you.
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Reviewed in the United States on May 30, 2026
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Verified Purchase
K.C.
Los Angeles, US
★★★★★ 1
One day of use, then it rubbed against my toes and caused cuts
Size: 9-9.5, Color: Black Denim Blue, Size: 9-9.5, Color: Black Denim Blue
I got these right before a trip to Costa Rica where we would be doing a lot of hiking, some tubing, and be in and out of water. They felt great when I first tried them on and I was optimistic. Our first day, we hiked a total of about 5 miles in the forest and along a river, with some swimming in pools throughout the hike. These weren't difficult trails, but a mix of gravel, rock, dirt, etc. The shoes felt fantastic and were comfortable all day. Later that evening, after they had mostly dried out, we did another mile or so to some other pools and I had no problem. During that hike I was so happy I was actually talking to my kids about what great things I was going to say in a review. The following day however, as soon as I put on the sandals, just walking to the hotel pool, the top of the shoe, just above my big toes, was bending and rubbing against my toes. It was very noticeable and I took them off and made sure there was no sand or anything else causing the irritation. I had no other choice that day and we ended up back on a similar trail, hiking a total of about 1.5 miles, with it rubbing against my toes the entire time. I tried both tightening and loosening the shoes and changing my stride to step more flat footed so they wouldn't bend at the back of my step, but that didn't help. Neither did getting them wet again, hoping to soften something up. By the time we were half way through that hike, there were visible raw spots on top of both my big toes. By the time we were done, they had become sores and very painful. The following day, we walked on the sidewalk to breakfast about three blocks away and it hurt bad enough that I found a store and bought a pair of flip-flops instead. I haven't worn the sandals since. I can't tell exactly what's going on inside the shoe, but I think the leathery part of the shoe is pushing down at the natural break in the toe area when I step, and the mesh is rubbing. Since I've worn them outside and been swimming in them, I can't return them, but they're basically useless after one good day.
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Reviewed in the United States on November 29, 2025
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Verified Purchase
Amazon Customer
Massapequa, US
★★★★★ 5
Great headphones!
Color: Black
Great headphone! They work well and sound quality was pretty good. Definitely worth the money. I love that they’re not inserted into the ear. It allows me to hear things going on around me but not so much that I can’t hear my music. They’re pretty comfortable too! I have smaller ears and the earbuds that you put into your ear tend to hurt after some time. These typically don’t.
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Reviewed in the United States on May 13, 2026
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e03
San Leandro, US
★★★★★ 5
If you’re curious about open ear earphones give these a try
Color: Black, Color: Black
I don’t normally review but these are genuinely great quality, especially for the price! I was skeptical about open ear for sound quality/comfort to be honest and the first couple days I used them they were a but uncomfortable and my ears hurt after a while, but once you figure out how to fit them properly and get used to it they’re actually incredibly comfortable, so much that I often forget I have them on lol. The part that hooks on your ear is a soft bendy plastic, silicone-like so it’s pretty forgiving for different ear shapes. I love the dual connecting Bluetooth as well, super useful for switching between tasks on different devices. The sound quality is pretty on par with higher end options and it doesn’t really leak sound much either, even though it’s open ear which is great, also allows you to still hear your surroundings really well so good for commuting/out and about/office work. Great battery life and they charge quickly in the case, I work in video editing so use them pretty much all day and with the case they last several days before needing a recharge. I’ve had them for a couple months now I think and I’m really glad I went with this option. Absolutely the best option I’ve tried around this price point, anker products as a whole I’ve found are really great quality at a very reasonable price.
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Reviewed in the United States on April 16, 2026
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Verified Purchase
Diem
Bozeman, US
★★★★★ 5
COMFORT KING 👑✨
Color: White
I struggle finding headsets that don't bother my ears OR cause headsets 🙈 others will just fall right out which gets super annoying... These on the other hand, are like air!! I genuinely cannot even tell I'm wearing them! The ear piece is adjustable for all (or most) ears! The sound quality is amazing while still being able to hear what's going on around me. They don't fall out, the adjustments help with that too! Even on the tightest setting, it's not uncomfortable, the silicone really feels like butter. My only semi-complaint is that the battery doesn't seem to last very long, but I've only used them out of the box 🙈 I'm gonna charge a full day and see how they do! Honestly not a major problem anyway because I only wear one for work, when one dies I just swap to the other. Connectivity is quick and easy! If you are picky about ear comfort, I promise you, these will not let you down!! ABSOLUTELY WORTH THE MONEY
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Reviewed in the United States on May 15, 2026

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