The S4 MK 677 Stack: Benefits, Side Effects, and Recommendations

You’re on the quest for the ultimate bodybuilding stack, and S4 MK 677 might just be your answer. This potent combination of S4 (Andarine) and MK 677 (Ibutamoren) is a well-known stack in the fitness community, favored for its potential to enhance muscle growth, strength, and recovery. You’re about to dive into the world of SARMs and growth hormone secretagogues, and it’s guaranteed to be an enlightening journey.

The S4 MK 677 stack is not your average supplement stack. It’s a powerful duo that’s been making waves in the bodybuilding and fitness world. With S4’s reputation for promoting lean muscle mass and MK 677’s potential for boosting growth hormone levels, you’re looking at a stack that could potentially transform your physique and performance.

In this article, you’ll learn everything you need to know about the S4 MK 677 stack. From how it works, its potential benefits, and even down to its possible side effects. You’re about to embark on a comprehensive exploration of this popular stack, arming you with the knowledge to make informed decisions about your bodybuilding journey.

Key Takeaways
  • 💪 The S4 MK 677 stack combines S4 (Andarine) and MK 677 (Ibutamoren), which are popular for their potential to enhance muscle growth, strength and recovery.
  • 🎯 S4 is known for promoting lean muscle mass, while MK 677 can boost growth hormone levels. The combination of these can transform physique and performance.
  • 🏋️ The stack can lead to visible gains, increased energy levels, and quicker recovery times.
  • 🥄 Recommended dosage for S4 is between 25mg to 75mg per day, and for MK 677 it’s between 10mg to 25mg per day, typically taken in cycles of 8 to 12 weeks.
  • 😷 Potential side effects include vision changes and testosterone suppression. It’s essential to tweak dosages based on body reactions and adhere to a post-cycle therapy regimen.

What is the S4/Andarine + MK 677/Ibutamoren stack?

S4 MK 677 Stack

The S4 MK 677 Stack—it’s like your secret weapon in the fitness world. Let’s break down its anatomy to better understand why it’s a top choice among bodybuilding aficionados. First off, S4, or Andarine, is noted for its ability to stimulate muscle growth. It’s a selective androgen receptor modulator—cutting fat while elevating lean muscle.

Second, we’ve got the MK 677 element known as Ibutamoren. It primarily functions as a potent, long-lasting growth hormone secretagogue. You’re tapping into your body’s natural ability to produce growth hormone with this wonder supplement.

  • Struggling to gain muscle? This stack’s for you.
  • Need a recovery booster? Yeah, this combo’s got your back.

Ever pondered: “What’s the stack’s role in my workout?”

Every time you hit the gym full throttle, you might find yourself brimming with anticipation for that post-workout mirror check. It’s all about witnessing the fruits of your labor, right? What if you could rev that up? That’s the magic of the S4 MK 677 Stack. You’re not only working harder, but you’re also working smarter.

Equipped with this potent stack, your body finds the strength to plow through your workout routine. You’ll notice visible gains, an uptick in your energy levels, and a faster recovery time.

Let’s talk side effects. Both S4 and MK 677 have some possible effects to be aware of. Headaches, weird dreams, and a change in the rhythm of your heart are potential side effects.

First component of the stack: S4 (Andarine)

What is S4?

Now that you’re familiar with the S4 MK 677 stack, let’s focus on the S4 component, Andarine. Falling under the category of SARMs (Selective Androgen Receptor Modulators), S4 is a trailblazer in this ever-evolving world of fitness supplements. It offers a unique blend of benefits, earning it a firm spot in the hearts of fitness enthusiasts world-over.

How does S4 work?

S4 works by binding itself to the androgen receptors in your body. This is the same place where steroids would attach too. But S4 is not a steroid. Here’s how it’s different.

Steroids create anabolic and androgenic effects equally throughout the body, whereas S4 creates an anabolic effect that’s primarily concentrated in your skeletal muscle. This results in no harmful impact on your heart, prostate, or liver, unlike steroids.

Notably, S4 denotes selective protein synthesis. It’s targeted, it’s strategic, and in essence, it’s a smarter muscle promoter. It has the ability to promote lean muscle mass gain while simultaneously combating muscle wastage.

Potential benefits of S4

Excited about learning S4’s benefits? You’ll quickly see why it’s grown such a fan base. Here are the potential benefits of S4:

  • Muscle growth: S4 is well known for boosting muscle growth. While the results won’t be as dramatic as you might get from steroids, they’ll undoubtedly be more long-lasting. Plus, S4 won’t give you the side effects associated with steroids.
  • Fat loss: S4 isn’t just about building muscle, it’s about burning fat too. By improving your body’s ability to oxidize fat, S4 can help you to lean out and reach your shred goals.
  • Bone health: S4 also plays a significant role in bone health. It helps to strengthen your bones by increasing bone density, which is especially beneficial in preventing fractures. These are only a few of S4’s benefits. More await you as you continue exploring S4’s power in this muscle-building journey. Moreover, remember that the results will differ from person to person, since everyone’s body reacts differently. Enjoy this journey towards a fitter body with S4 to aid you along the way.

So, that’s the S4 side of our S4 MK 677 stack. What about the MK 677 side? Let’s dive in and find out what MK 677 has to offer next.

Second component of the stack: MK 677 (Ibutamoren)

What is MK 677?

Often coupled with S4 in the well-known S4 MK 677 stack, MK 677, or Ibutamoren, is another favorite in the fitness landscape. Unlike S4, MK 677 isn’t a SARM but a growth hormone secretagogue that stimulates the secretion of the growth hormone (GH) and insulin-like growth factor 1 (IGF-1).

How does MK 677 work?

MK 677 acts on the ghrelin receptor, a potent, long-acting, oral ghrelin mimetic. With a keen ability to mimic ghrelin—the hunger hormone—MK 677 ramps up growth hormone and IGF-1 levels in your body without affecting cortisol production. Cortisol, often named ‘stress hormone,’ can negatively impact immune function and bone formation and impede other growth hormones if in excess. Hence, MK 677’s ability to leave cortisol untouched is a plus.

What does this mean for you?

It means proportionally increased lean muscle mass and unimaginably fast recovery times. It’s also lauded for its potential to enhance quality sleep and possibly counteract aging and age-related diseases.

Potential benefits of MK 677

MK 677 goes beyond bodybuilding and muscle growth. In numerous studies, here are a few potential benefits linked to this incredible compound:

  • Increase in lean body mass: It’s a favorite amongst bodybuilders and athletes for its reputed ability to enhance lean body mass and reduce muscle wasting. This property makes MK 677 useful not only for those into fitness but also for individuals suffering from conditions related to muscle atrophy.
  • Better bone health: A tremendous upside of MK 677 is its potential to boost bone density. In research, adults who got MK 677 regularly showed increased bone turnover — the process where old, damaged bone is replaced with new, healthy bone.
  • Improved sleep quality: Another significant ace up MK 677’s sleeve is its potential to improve sleep quality, as higher GH and IGF-1 levels can support better sleep cycles.

Why Stack S4 and MK 677 together?

Stack Benefits

When it comes to achieving your fitness goals, stacking S4 and MK 677 can deliver impactful results. You’d be amazed at the synergistic effects and potential muscle-building benefits that this combo stack offers.

Synergistic Effects

Stacking S4 and MK 677 isn’t just about doubling the benefits. It’s about creating a powerful synergy that amplifies the effects of each compound. Let’s break it down. First, here’s a chart:

S4 MK 677 stack explained in a diagram

S4, also known as Andarine, primarily focuses on lean muscle mass gain and fat loss. It doesn’t harm your heart, prostate, or liver, making it an ideal SARM that many fitness enthusiasts prefer.

Being a growth hormone secretagogue, MK 677 stimulates the secretion of growth hormone and insulin-like growth factor 1, commonly known as IGF-1. It acts on the ghrelin receptor, with the ability to increase lean muscle mass, enhance recovery times, boost bone health, and improve sleep quality.

But when you stack these two together, they potentiate each other, giving you the combined benefits of both compounds and more.

Potential Muscle-Building Benefits

As you combine S4 and MK 677, it leads to a spike in your muscle-building efficiency. When S4 helps in achieving lean muscle mass, MK 677 jumps in to enhance both your recovery times and sleep quality.

In a nutshell, S4 primarily targets muscle gain and fat loss, whereas MK 677 serves as a supportive component in the stack, improving other vital factors like recovery time and sleep quality. The better your sleep quality, the better your body can repair and rebuild itself. The faster your recovery times, the more frequently you can workout without getting exhausted.

So, if you’re looking to boost your muscle-building progress and accelerate fat loss, the S4 MK 677 stack might be the ticket. However, it’s essential to adopt a balanced diet and regular workout regime to achieve the best results. Always remember, S4 and MK 677 are supplements that aid your efforts, not magic pills.

While the S4 MK 677 stack shows promising results, it might not be suitable for everyone. Make sure to consult with a healthcare professional or a certified personal trainer before initiating this stack to ascertain that it is the right choice for your fitness journey.

How to use the S4 and MK 677 together for maximum results

Dosage and Cycle

Once you’ve decided to incorporate the S4 MK 677 stack into your fitness regimen, the proper dosage and cycling duration are critical for optimal results. Keep in mind that these guidelines are general, so it might be the best option to consult with a healthcare professional or certified personal trainer before your journey to ensure maximum benefits and minimum side effects.

Dosage Recommendations

Andarine (S4) is typically recommended at doses between 25mg to 75mg per day. Beginning with a moderate dose and observing your body’s reaction is a smart approach to start with. Record any side effects and performance changes throughout this phase. Your observations can help guide subsequent dosing decisions.

On the other hand, MK 677 (Ibutamoren) gets its best results with doses that fall between 10mg to 25mg per day. Starting at the lower end of this range and slowly working your way up is advisable. Remember, patience is the key to success. Gradually increasing the dosage allows your body to adjust and helps to prevent unwanted side effects.

Cycling and Duration

When it comes to cycling i.e., periods of taking the stack followed by periods of not taking it, the most common practice is a cycle length of anywhere between 8 to 12 weeks. This allows the body time to adapt to the stack, and a break period is beneficial to prevent long-term downregulation metabolic receptors.

Keeping a consistent cycle is just as important to your overall success with the S4 MK 677 stack. It’s not unusual for users to take their stack for 8 weeks, then pause for 4 weeks. This type of cycle can be repeated 2 to 3 times per year, depending on your specific goals and individual tolerance.

Remember, everyone’s body is unique – your ideal dosage and cycle duration might vary based on your individual physiology, fitness goals, and tolerance. Tailoring the S4 MK 677 stack to your own needs is the real secret to unlocking the full potential of this powerhouse combo. Whether you’re shattering plateaus, aiming for new personal bests, or dialing in your physique, the S4 and MK 677 stack is a profound tool to keep in your bodybuilding arsenal.

Experiencing any discomfort or unpleasant side-effects should signal to stop its usage temporarily. If issues persist consult a trusted healthcare provider.

Stack and Save at Chemyo

$134.98 159.98
3rd Party Lab Tested: >98%+ Purity Guaranteed
Save big on MK 677 stacks at Chemyo. Use code sarmsdotio at checkout to save an additional 10% OFF!

Let’s move on to some common pros and cons associated with the usage of the S4 MK 677 stack.

How to use the S4 and MK 677 together for maximum results

Potential Side Effects

While S4 MK 677 stack offers a host of benefits, it’s equally important to be aware of the potential side effects. Keep in mind, these possible effects generally occur when taking doses higher than recommended, or when you’re not giving your body enough time to adapt to the compound. Irrespective, it’s essential to monitor your body’s reaction and to make adjustments as needed.

Vision Changes

One potential side effect linked specifically with the use of S4, or Andarine, is alterations in vision. Users have reported a yellow tint or slight yellowish vision during night-time. Why does this happen? Well, S4 binds to the eye’s receptors, which might be responsible for the temporary color change. However, it’s important to note, this impact is typically short-lived and reverts to normal once the compound is discontinued.

Remember, this is not a common side effect among all users, only a fraction have reported experiencing it. Since vision is critical, if you do notice any unusual changes, do not hesitate to contact a healthcare professional.

Testosterone Suppression

The S4 component in the stack also may lead to slight testosterone suppression. During a cycle, it’s possible that the body’s natural testosterone production decreases. Don’t panic though – this is part of your body adjusting to the compound.

However, to prevent this suppression it’s recommended you follow proper post-cycle therapy (PCT). A good PCT can help restore your body’s natural testosterone production. Though if you notice significant fatigue, changes in sex drive, or extreme mood swings, it’s strongly recommended that you consult a healthcare professional.

Concluding thoughts and research citations


The S4 MK 677 stack’s popularity in the fitness world isn’t without reason. Its synergistic effects and muscle-building potential make it a potent tool for those serious about their gains. But remember, it’s not without its potential side effects. Vision changes and testosterone suppression are real concerns that you’ll need to keep an eye on. Manage these by closely monitoring your body’s reactions, tweaking your dosage as necessary, and adhering to a proper post-cycle therapy regimen. And don’t forget, it’s always wise to seek professional medical advice before embarking on your S4 MK 677 journey. Your health should always take precedence over your fitness goals. So, tread wisely, stay informed, and you’ll be well on your way to achieving your fitness objectives with the S4 MK 677 stack.


  1. Almeida, M., Laurent, M., Dubois, V., Claessens, F., O’Brien, C., Bouillon, R., … & Manolagas, S. (2017). Estrogens and androgens in skeletal physiology and pathophysiology. Physiological Reviews, 97(1), 135-187.
  2. Cawley, A., Smart, C., Greer, C., Lau, M., & Keledjian, J. (2015). Detection of the selective androgen receptor modulator andarine (s‐4) in a routine equine blood doping control sample. Drug Testing and Analysis, 8(2), 257-261.
  3. Christiansen, A., Lipshultz, L., Hotaling, J., & Pastuszak, A. (2020). Selective androgen receptor modulators: the future of androgen therapy?. Translational Andrology and Urology, 9(S2), S135-S148.
  4. Demircan, T., Yavuz, M., & Bölük, A. (2023). Andarine plays a robust in-vitro anti-carcinogenic role on a549 cells through inhibition of proliferation and migration, and activation of cell-cycle arrest, senescence, and apoptosis..
  5. Komrakova, M., Nagel, J., Hoffmann, D., Lehmann, W., Schilling, A., & Sehmisch, S. (2020). Effect of selective androgen receptor modulator enobosarm on bone healing in a rat model for aged male osteoporosis. Calcified Tissue International, 107(6), 593-602.
  6. Narayanan, R., Ahn, S., Cheney, M., Yepuru, M., Miller, D., Steiner, M., … & Dalton, J. (2014). Selective androgen receptor modulators (sarms) negatively regulate triple-negative breast cancer growth and epithelial:mesenchymal stem cell signaling. Plos One, 9(7), e103202.
  7. Bennett, K., Langmead, C., Wise, A., & Milligan, G. (2009). Growth hormone secretagogues and growth hormone releasing peptides act as orthosteric super-agonists but not allosteric regulators for activation of the g protein gαo1 by the ghrelin receptor. Molecular Pharmacology, 76(4), 802-811.
  8. Lee, J., Kwon, A., Chae, H., Lee, W., Kim, T., & Kim, H. (2018). Effect of the orally active growth hormone secretagogue mk-677 on somatic growth in rats. Yonsei Medical Journal, 59(10), 1174.
  9. Murphy, M., Bach, M., Plotkin, D., Bolognese, J., Ng, J., Krupa, D., … & Gertz, B. (1999). Oral administration of the growth hormone secretagogue mk‐677 increases markers of bone turnover in healthy and functionally impaired elderly adults. Journal of Bone and Mineral Research, 14(7), 1182-1188.
  10. Murphy, M., Plunkett, L., Gertz, B., He, W., Wittreich, J., Polvino, W., … & Clemmons, D. (1998). Mk-677, an orally active growth hormone secretagogue, reverses diet-induced catabolism1. The Journal of Clinical Endocrinology & Metabolism, 83(2), 320-325.
  11. Nass, R., Pezzoli, S., Oliveri, M., Patrie, J., Harrell, F., Clasey, J., … & Thorner, M. (2008). Effects of an oral ghrelin mimetic on body composition and clinical outcomes in healthy older adults. Annals of Internal Medicine, 149(9), 601.
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.

Have a question? Leave a comment below.

Leave a reply