Three Ostarine Stacks for Bulking, Cutting, and Strength

Are you trying your first SARMs stack? Chances are, one of the first SARMs you tried was Ostarine? MK-2866 is a popular starting block for new users looking into performance enhancement.

GTX Laboratories are the original developers of Ostarine, gaining the license for the development from the University of Tennessee Research Foundation. Merck & Company has the formal rights to Ostarine development, and it’s not available for commercial or medical use anywhere in the world.

Also known as “Enbosarm,” Ostarine is one of the original SARMs finding its way into the bodybuilding and fitness industry. It has a similar chemical structure to Andarine (S4) but produces a different result in users.

What are the Effects of Using Ostarine?

Ostarine Effects

According to a lab mice study, Ostarine is as effective as the potent androgenic steroid dihydrotestosterone in restoring pelvic floor muscle size.

Ostarine also shows an affinity for activating muscle stem cells, also known as” satellite cells.” These cells are instrumental in muscle regeneration after exercise stimulation.

Research shows that unlike Anabolic Androgenic Steroids (AAS), Ostarine also helps to regenerate and stimulate connective tissues, an important feature in injury healing and prevention.

Ostarine works by increasing the production of insulin-like growth factor (IGF-1). As a result, the user experiences an increase in strength and performance in the gym.

Users also notice a significant increase in lean muscle tissue growth, with a single 4-week cycle at moderate dosages adding up to 6-lbs of lean tissue in some users.

Is it safe to stack Ostarine with other SARMs?


Most users report Ostarine provides minimal side effects. However, increasing the dose beyond 35mg a day or stacking it with other compounds might cause the emergence of side effects in some users.

For this reason, newcomers to performance enhancement should avoid a stacking protocol for their first experience.

Stacking is for advanced users that understand how these compounds affect their bodies. By jumping into the deep end of the pool with your first SARMs experience, you’re likely to find yourself experiencing side-effects that put you off using performance enhancers for life.

As a newbie to performance enhancement, you need to get a baseline understanding. For instance, if you were about to run a cycle with four compounds, break that up into four cycles using each compound individually. On your fifth cycle, you can try all four compounds together.

Using this strategy lets you collect data on your response to the SARMs or SARM-like compounds in your first four cycles.

If something goes wrong when you stack them, you’ll have an easier time managing the side effects and finding the problem compound causing the sides.

There’s no need to go full title on your first cycle if you plan on doing this for the long run. Stacking with minimal experience is always a bad idea.

Flexing abs while on a cycle of Ostarine.

What are the Top 3 Ostarine SARMs Stacks?

Example Stacks

Ostarine is one of the most versatile SARMs available. This product helps you shed body fat, gain muscle, and harden up, all with one formulation.

It’s a great base for a SARMs stack, allowing you to add other core compounds around it to meet your goals. We curated three Ostarine stacks we feel offer you the best performance in three areas of goal setting.

Our three stacks help you get the most out of your cycle. We gave you the base products for your stack and included a fourth option for advanced users that have experience with previous stacks.

Most users start with a 25mg daily dose. Ostarine has a 24-hour half-life, meaning you only need to dose it once a day. For best results, take your Ostarine in the morning.

Cycle lengths of up to 10-weeks are suitable, with average use being six to eight weeks.

💡 Tip: You can find high quality SARMs vendors on the Source List

#1 Bulking/ Muscle Building

Ostarine is a good choice for a base for your bulking cycle. It offers most users a side-effect free experience, allowing them to stack with more aggressive compounds, like the myostatin inhibitor, YK-11.

YK-11 is a potent muscle builder, and combining it with RAD-140 adds in some dry gains to supercharge your cycle. Ostarine is the glue that holds everything together, and if you want to really see optimal results, try running these three compounds alongside MK 677.

Week 1 – 10mg Ostarine / 10mg YK-11 / 10mg RAD-140 / 10mg MK 677

Week 2 – 15mg Ostarine / 10mg YK-11 / 10mg RAD-140 / 10mg MK 677

Week 3 – 15mg Ostarine / 10mg YK-11 / 10mg RAD-140 / 10mg MK 677

Week 4 – 20mg Ostarine / 10mg YK-11 / 10mg RAD-140 / 10mg MK 677

Week 5 – 20mg Ostarine / 15mg YK-11 / 15mg RAD-140 / 20mg MK 677

Week 6 – 25mg Ostarine / 15mg YK-11 / 15mg RAD-140 / 20mg MK 677

Week 7 – 25mg Ostarine / 15mg YK-11 / 15mg RAD-140 / 20mg MK 677

Week 8 – 25mg Ostarine / 15mg YK-11 / 15mg RAD-140 / 20mg MK 677

Week 9 – 30mg Ostarine / 15mg YK-11 / 20mg RAD-140 / 20mg MK 677

Week 10 – 35mg Ostarine / 15mg YK-11 / 20mg RAD-140 / 20mg MK 677

#2 Dieting/ Contest Prep

Ostarine is the ideal base for your cutting stack. The MK-2866 provides you with lean gains and plenty of growth. Combining it with SR9009 (Stenabolic) and S4 (Andarine) is a recipe for grainy muscularity, paper-thin skin, and hose-pipe vascularity.

Trying to stay enthusiastic about training and cardio when you’re running low calories is challenging. However, the additional energy from your stack gives you everything you need to power through your workouts.

Try this stack for shredding body fat for the stage.

  • SR9009, S4, Ostarine
  • Additional for advanced users: MK 677

Week 1 – 10mg SR9009 / 25mg S4 / 10mg MK-2866 / 10mg MK 677

Week 2 – 10mg SR9009 / 25mg S4 / 10mg MK-2866 / 10mg MK 677

Week 3 – 10mg SR9009 / 25mg S4 / 15mg MK-2866 / 10mg MK 677

Week 4 – 10mg SR9009 / 25mg S4 / 15mg MK-2866 /10 mg MK 677

Week 5 – 15mg SR9009 / 50mg S4 / 20mg MK-2866 / 20mg MK 677

Week 6 – 15mg SR9009 / 50mg S4 / 20mg MK-2866 / 20mg MK 677

Week 7 – 15mg SR9009 / 50mg S4 / 25mg MK-2866 / 20mg MK 677

Week 8 – 20mg SR9009 / 50mg S4 / 25mg MK-2866 / 20mg MK 677

Week 9 – 20mg SR9009 / 50mg S4 / 30mg MK-2866 / 20mg MK 677

Week 10 – 20mg SR9009 / 75mg S4 / 35mg MK-2866 / 20mg MK 677

#3 Recomposition/ Muscle Hardening

Recomping is a massive challenge for any newcomer to performance enhancers. Your first cycle enables you to lose body fat and build muscle simultaneously, something that’s unheard of in bodybuilding and fitness circles.

If you have experience using Ostarine or other SARMs, give this stack a try for your next recomp.

  • Ostarine, Ligandrol, RAD-140
  • Additional for advanced users: MK 677

Week 1 – 10mg Ostarine / 10mg Ligandrol / 10mg RAD-140 / 10mg MK 677

Week 2 – 10mg Ostarine / 10mg Ligandrol / 10mg RAD-140 / 10mg MK 677

Week 3 – 10mg Ostarine / 10mg Ligandrol / 10mg RAD-140 / 10mg MK 677

Week 4 – 10mg Ostarine / 10mg Ligandrol / 15mg RAD-140 / 10mg MK 677

Week 5 – 15mg Ostarine / 10mg Ligandrol / 15mg RAD-140 / 10mg MK 677

Week 6 – 15mg Ostarine / 20mg Ligandrol / 15mg RAD-140 / 20mg MK 677

Week 7 – 20mg Ostarine / 20mg Ligandrol / 20mg RAD-140 / 20mg MK 677

Week 8 – 25mg Ostarine / 20mg Ligandrol / 20mg RAD-140 / 20mg MK 677

Week 9 – 30mg Ostarine / 20mg Ligandrol / 20mg RAD-140 / 20mg MK 677

Week 10 – 35mg Ostarine / 20mg Ligandrol / 20mg RAD-140 / 20mg MK 677

Can you stack Ostarine with other steroids, peptides, or prohormnoes?

Ostarine + AAS Stack

Sure, Ostarine is a popular “front-loader” for AAS users. You get the advantage of starting your cycle with a liver-friendly SARM instead of a toxic 17-aa methylated oral AAS or prohormone.

Ostarine offers you a similar effect to oral AAS like Anavar or prohormones like Cyanostane or Dimethezine.

However, if your cycle already has several AAS orals, it’s better to stay away from Ostarine. Adding more components into your cycle could put your health at risk.

Using anabolic steroids such as testosterone with Ostarine is possible with a doctor's supervision.

What Results Can I Expect with Ostarine SARMs Stacks?


Ostarine-based stacks are excellent for achieving a variety of physique goals. Ostarine solo cycles allow users to make dry, lean gains without adding too much subcutaneous water into their bodies.

Due to its versatility, Ostarine is suitable for cutting, bulking, or recomping. It works as a stacking component with just about every other SARM or SARM-like compound.

It’s a good idea to taper your way into an Ostarine cycle. This strategy lets you assess the effect of increasing each compound’s dosage before moving onto the next stage of the cycle.

As a result, you can easily mitigate side effects when they emerge, and you know the compound causing the problem.

Ostarine has a quick loading effect, making it a top choice for bodybuilders and fitness athletes looking to “front-load” the beginning of AAS cycles. At the same time, they wait for longer-ester testosterones to kick in.

You should feel the results of taking Ostarine after day three on a solo cycle. By the end of the first week, you’ll notice your pumps in the gym are stronger, almost splitting your skin.

Vascularity increases as you get leaner and strength increases consistently after the first week until the end of your cycle. You’ll also notice an increase in stamina, allowing you to get more reps out with higher weight.

Combining Ostarine with other SARMs or SARM-like products provides the user with amplification in the drug’s effects. Ostarine is one of the oldest SARMs, and it remains one of the most popular for a reason – it provides results.

What are the Side Effects of Running Ostarine SARMs Stacks?

Side Effects

Ostarine is one of the original SARMs used in performance enhancement cycles. As a result of its extensive use, there is quite a bit of anecdotal user data available on this SARM.

Most users report no severe side effects during Ostarine use, even when combining it with other SARMs in a stack. However, some users report the emergence of side effects with large doses.

Some of the reported side effects in Ostarine users are the following.

  • A lowered sense of well being after nine days of use.
  • Pain occurring in the testes.
  • Joint pain and dryness in the joints.
  • Problems with ED.
  • Low energy and depression.

None of the side-effects present an immediate physical reaction to Ostarine, and most users report side-effect-free cycles.

However, stacking your Ostarine with other SARMs in a cycle using multiple compounds can increase the prevalence and intensity of side effects.

For this reason, stacking is only suitable for experienced users that understand how their body responds to SARMs.

If this is your first cycle, and you intend to run a stack, we implore you to think again. Taking multiple compounds at once can be challenging to manage and ruin your experience.

It’s a better strategy to run two or three compounds in separate cycles and then a stacking cycle where you combine all there to see the synergistic effect.

Does Stacking Ostarine SARMs Cause “Shutdown?”


“Shutdown” is a term describing the halt of natural testosterone production in your body. The Hypothalamic Pituitary Testicular Axis (HPTA) governs the production of testosterone in the male body.

When you introduce exogenous testosterone into the body through intramuscular injection, the hypothalamus detects it. In response, it stops your natural production through the HPTA.

SARMs do not cause this suppressive effect because they work with androgen receptors only. As a result, there are no unpleasant estrogenic side effects associated with Ostarine use.

Do I Need to Run an Aromatase Inhibitor with Ostarine SARMs?

Aromatase Inhibitor (AI) + Ostarine

There are some claims that users experience estrogenic sides at high doses of 35mg or more per day. If that’s the case for you, you can use an Aromatase Inhibitor to prevent gynecomastia from forming in your breast tissue.

Hoenstly though, if you are experiencing estrogen sides from Ostarine, then you most likely got sold a fake product. Ostarine doesn’t affect E2 levels on it’s own, and if anything, it will lower them a bit. When I read someone getting high E sides from Ostarine, my first thought was that they were mistakenly ingesting something like D-Bol.

Stacking Ostarine with multiple other compounds might increase estrogenic side effects. If that’s the case for you, try backing off your dose to see if you reduce the side effects.

Adding an AI like Aromasin or Anastrozole into your stack might cause your joints to dry out, exposing you to injury. The only way to monitor your estrogen levels on cycle is through bloodwork analysis.

Do I Need a PCT when Stacking Ostarine with other SARMs?

Post Cycle Therapy

Yes and no, the only real way to find out if you need a pharmaceutical-grade PCT or and OTC option is through bloodwork analysis.

Visit a life extension clinic or your doctor, and ask them for a hormone panel. Your doctor draws blood and sends it for analysis. They read the data, comparing your results for free testosterone and thyroid hormone to healthy people in your age demographic.

Suppose the cycle suppressed your natural test production. In that case, the doctor might script you an anti-estrogen medication like Nolvadex or Clomid to help your Hypothalamic Pituitary Testicular Axis (HPTA) recover from the effects of your cycle.

Typically, solo cycles of Ostarine only require an OTC PCT solution like a test-booster.

However, stacking multiple compounds for extensive cycles can have a slightly suppressive effect on your HPTA. The only way to know for sure is with bloodwork.

For best results, get your bloodwork done before you start your cycle. This data gives your doctor a baseline to work with when establishing your hormone profile post-cycle.

How Many Times Can I Run an Ostarine SARMs Stack Each Year?

Cycle Frequency

Using short cycles of four to six weeks, you could fit up to four cycles into a year. Longer ten or 12-week cycles limit you to two a year.

Running more cycles than this won’t increase your gains. SARMs work by docking with androgen receptors.

While you have millions of these receptors in your body, eventually, you saturate them and start to see diminishing returns on your cycle.

Cycling gives you time to flush out your receptors, preparing them for the next stack. Using this strategy, you can make progress for years.


Ostarine is a banned substance by the World Anti-Doping Agency (WADA). Any athlete caught using Ostarine receives an automatic 2-year suspension.

WADA banned Ostarine back in 2008, and plenty of athletes test positive for the substance each year. From rugby players to MMA fighters, the list of Ostarine violations concerns in professional sports.

Therefore, if you compete in professional sports, it’s a good idea to avoid using Ostarine in your stack.

Should I Use Capsules or Liquids for My Ostarine SARM Stack?

Those ordering SARMs from international sources should opt for powders, encapsulated products, or pills. Avoid ordering liquid SARMs with your stack.

Liquid SARMs are sensitive to light and temperature. A significant drop or increase in ambient temperatures results in the “denaturing” of the SARM. If denaturing occurs, it dramatically reduces the potency of your SARM.

During the transportation of liquid SARMs from the US or EU to Australia, the products undergo significant fluctuations in ambient temperatures that affect your product.

By ordering tablets, capsules, or powders, you avoid this issue. These products are stable during temperature changes, ensuring their potency.

US readers should stick to liquids if possible, as they are the default best option when shipping distance isn’t of concern.

Where can I buy Ostarine from?

Buy Ostarine

Finding Ostarine or any other SARMs at your favorite local supplement store isn’t going to happen. The feds states Ostarine is a banned substance with no medical use.

Therefore, the sales and distribution of Ostarine and SARMs in can get sticky. If you want to purchase SARMs, you’re going to have to find a source. There are hundreds of sources online, and all of them promise SARMs with the highest purity.

However, the reality is most of these sites are nothing more than marketing hype. As a buyer, you’re only interested in working with companies that offer you two things.

  • On-site third-party lab testing results
  • Guaranteed delivery

💡 Tip: You can find high quality SARMs vendors on the Source List

Almost all websites understand your concern is purity when making your purchase. Since SARMs are not available commercially through your doctor, even with an Rx script. Instead, you have to deal with Underground Laboratories (UGLs).

UGLs source its raw materials for SARMs products from various sources. The lowest-quality products come from Chinese raw materials, while US and EU sources offer the best purity.

The only way to determine the origin and purity of the SARM raw materials is through legitimate third-party testing at an independent laboratory.

The third-party lab issues a “Certificate of Analysis” on the batch tests. The COA tells you the contents of the raw materials, the purity of the SARM, and the origin or batch number.

Many sites promise they use third-party testing on their products. The reality is very few actually do it. Ensure your supplier posts the Certificate of Analysis on the product page or its website for your review.

If the website doesn’t have COAs available, it’s a red flag, and you should avoid ordering from these sources.

An issue facing Australians ordering from international sources – is the delivery of your SARMs. Stacks costs a decent amount of money, and you could spend $200 to $300 on your order.

The last thing you need is for customers to intercept your parcel and seize your stack. If that happens, you need to work with a source that guarantees delivery. If you experience a seizure at customs, the supplier resends your order free of charge.

Finding a source offering guaranteed delivery is worth the few dollars extra you pay at checkout.

How to find a reputable supplier of MK 2866 in 2023

Recommended Sources

Our Verified Source Program is your go-to guide for finding the best online suppliers of top-quality SARMs. We unpack everything you need to know about all the top local and international sources for SARMs online.

Our goal is to provide a list of the top suppliers that deserve your business. Check out our Verified Sources Program and find the leading online SARMs suppliers right now.

Chris Jackson
Chris Jackson

Chris Jackson, co-founder of, is a renowned fitness blogger, physique model, and evolutionary bioscience researcher specializing in SARMs (Selective Androgen Receptor Modulators). His extensive work, characterized by cutting-edge research and practical training advice, has made a leading source for accurate, credible information on performance enhancers. With a dedication to improving the understanding and application of SARMs in optimizing human performance, his contributions have not only expanded public awareness but also shaped the conversation around these substances. Chris's pursuit of knowledge and commitment to sharing it continue to inspire many in their fitness journeys.

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