RAD 140 and MK 677 Stack: The Ultimate Guide

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The RAD 140 MK 677 stack combines two compounds that work through completely different mechanisms: RAD 140 (Testolone) drives muscle growth through androgen receptor activation, while MK 677 (Ibutamoren) elevates growth hormone and IGF-1 levels around the clock. Users running this stack for 8-12 weeks typically report 8-12 lbs of lean mass gains, noticeably faster recovery, and improved sleep quality, though individual results vary significantly based on training, diet, and genetics.

I have run Testolone and Ibutamoren together twice, and separately more times than I can count. The combination hits differently than either compound alone. RAD 140 on its own builds muscle, and MK 677 on its own improves recovery and sleep. Together, the anabolic push from Testolone meets the recovery and GH support from Ibutamoren, and the result is a cycle where you can push harder, recover faster, and actually see the scale move week over week.

That said, this is not a stack for someone who has never used a SARM before. Both compounds carry real side effects that need monitoring, and the combination adds complexity. If you are considering this stack, here is everything you need to know about dosing it, what to expect, and how to manage the downsides.

What is RAD 140 (Testolone)?

RAD 140, also known as Testolone, is a selective androgen receptor modulator (SARM) originally developed by Radius Health as a potential treatment for muscle wasting and breast cancer. It selectively binds to androgen receptors in muscle and bone tissue, promoting anabolic activity without the widespread side effects of traditional anabolic steroids.

RAD 140 works by activating androgen receptors in muscle cells, triggering protein synthesis pathways that drive muscle growth. Unlike testosterone, Testolone does not convert to estrogen or DHT, which means it avoids estrogenic side effects like gynecomastia and water retention. Research published in the journal Endocrinology showed RAD 140 demonstrated tissue-selective anabolic activity in preclinical models.

RAD 140 Benefits

The primary RAD 140 benefits include:

• Muscle growth: RAD 140 results typically show noticeable lean mass gains within 3-4 weeks, with most users reporting 5-8 lbs over an 8-week cycle
• Strength increases: Compound lift numbers tend to climb 10-15% over a full rad 140 cycle
• Fat loss support: Testolone can help preserve muscle during caloric deficits, making it useful for recomposition
• No estrogen conversion: Unlike many anabolic steroids, RAD 140 does not aromatize

The typical rad 140 dosage ranges from 10mg to 30mg per day, with 10-20mg being the sweet spot for most users. I personally find 15mg hits the best balance between results and side effects.

What is MK 677 (Ibutamoren)?

MK 677, also known as Ibutamoren, is not technically a SARM. It is a growth hormone secretagogue that mimics the action of the hormone ghrelin and binds to ghrelin receptors in the brain. This binding signals the pituitary gland to release growth hormone (GH), leading to sustained elevation of both GH and insulin-like growth factor 1 (IGF-1).

Unlike injectable growth hormone, MK 677 is orally active and does not suppress the body’s natural GH production. A study in the Journal of Clinical Endocrinology & Metabolism found that Ibutamoren increased GH secretion and IGF-1 levels in healthy young adults, with effects sustained over 12 months of administration.

MK 677 Benefits

The key mk 677 benefits include:

• Growth hormone elevation: MK 677 results show sustained GH and IGF-1 increases that support muscle growth, fat metabolism, and recovery
• Improved sleep quality: One of the most consistent user reports. GH is released primarily during deep sleep, and Ibutamoren enhances both GH levels and sleep depth
• Joint and connective tissue support: Elevated IGF-1 supports collagen synthesis and joint health, which matters when training heavy
• Appetite stimulation: This is a benefit or a drawback depending on your goals. During a bulk, the increased hunger from MK 677 makes it easier to hit caloric targets

The standard mk 677 dosage is 10-25mg per day. Most users settle on 15-20mg. Unlike SARMs, a typical mk 677 cycle can run for longer periods (some users run it 3-6 months) since it does not cause hormonal suppression on its own.

Why Stack RAD 140 and MK 677?

The reason this is considered one of the best SARMs stacks for bulking comes down to complementary mechanisms. The two compounds do not overlap in how they work, which means you get additive benefits without compounding the same side effect pathways.

How the Synergy Works

RAD 140 handles the anabolic drive. It binds to androgen receptors in muscle tissue and directly activates muscle protein synthesis. This is the primary muscle-building component of the stack.

MK 677 handles recovery, GH, and nutrient partitioning. By elevating growth hormone and IGF-1, Ibutamoren creates an environment where your body is primed to repair muscle tissue, store glycogen, and maintain an anabolic state even during rest.

Together, these two compounds create a cycle where:

• Muscle growth from RAD 140 is supported by the enhanced recovery environment from MK 677
• Sleep quality improves (MK 677 effect), which directly supports the anabolic processes RAD 140 initiates
• IGF-1 elevation from MK 677 amplifies the muscle-building signal from RAD 140’s androgen receptor activation
• Fat oxidation improves through GH elevation while lean mass increases through androgen receptor stimulation

The practical result: you train harder, recover faster, sleep better, and the gains show up sooner than they would with either compound alone.

RAD 140 and MK 677 Stack Results: What to Expect

Expectations should be grounded in reality. This sarms stack is effective, but it is not comparable to a full anabolic steroid cycle. Here is what this stack actually delivers for most users.

Weeks 1-3: Initial Phase

Do not expect dramatic changes. RAD 140 takes about 2 weeks to build to effective concentrations. MK 677 kicks in faster; you will notice increased appetite within days, and sleep quality often improves within the first week.

By week 3, most users feel a noticeable improvement in gym performance. Weights feel lighter, endurance improves, and recovery between sessions shortens.

Weeks 4-8: Peak Results Window

This is where the rad 140 results become visible. Strength climbs noticeably, muscle fullness increases, and the scale starts moving. Most users gain 1-2 lbs per week during this phase if nutrition is dialed in.

MK 677’s GH elevation is fully established by this point, and the MK 677 results become hard to miss. Skin quality improves, joints feel better under heavy loads, and sleep becomes deeper and more restorative. The appetite increase can be significant; if you are bulking, this is a benefit. If you are trying to recomp, you need to manage your intake.

I gained 10 lbs on my first RAD 140 and MK 677 cycle over 10 weeks, and roughly 7-8 lbs of that stuck after PCT and water loss. My bench went up 25 lbs and my deadlift jumped 30 lbs. These are not steroid-level numbers, but for a SARM stack, they are solid.

Weeks 9-12: Extended Cycle (Optional)

Some experienced users extend the stack to 12 weeks. Gains continue but at a slower rate, and RAD 140 side effects may become more pronounced, particularly testosterone suppression and lipid changes. If you extend past 8 weeks, bloodwork at week 8 is a good idea to check your liver enzymes and lipid panel.

RAD 140 Before and After: Realistic Expectations

Based on user reports and my own experience, here is what a typical rad 140 before and after looks like when stacked with MK 677:

Metric	Before	After (8-12 weeks)
Lean mass	Baseline	+8-12 lbs (some water weight drops post-cycle)
Body fat	Baseline	Slight reduction or maintained
Bench press	Baseline	+15-25 lbs
Squat	Baseline	+20-35 lbs
Recovery time	48-72 hours	24-36 hours
Sleep quality	Baseline	Noticeably improved

Results vary. Training intensity, diet quality, starting body composition, and individual response to both compounds all play a role. Someone with several cycles under their belt will see less dramatic changes than a first-time user.

RAD 140 and MK 677 Stack Dosage and Cycle

Getting the dosage right matters more than most people realize. Too low and you leave results on the table. Too high and you amplify side effects without proportional gains.

Recommended Dosage Protocol

Experience Level	RAD 140 Dosage	MK 677 Dosage	Cycle Length
Beginner	10mg/day	15mg/day	8 weeks
Intermediate	15mg/day	20mg/day	8-10 weeks
Advanced	20mg/day	25mg/day	10-12 weeks

RAD 140 Dosage Details

The researched rad 140 dosage range is 5-30mg per day. For this stack, 10-20mg is the practical range:

• 10mg/day: Good starting point for first-time users. Provides noticeable results with lower suppression
• 15mg/day: The sweet spot for most users. Balances muscle gain with manageable side effects
• 20mg/day: Upper end for experienced users. Stronger results but heavier testosterone suppression and potential lipid impact

I would not recommend exceeding 20mg in a RAD 140 stack. The additional gains from 25-30mg RAD 140 are marginal compared to the increase in suppression and liver stress.

MK 677 Dosage Details

The standard mk 677 dosage for this stack is 15-25mg per day:

• 15mg/day: Provides meaningful GH elevation with less appetite increase and water retention
• 20mg/day: Most commonly used dose. Good balance of results and side effects
• 25mg/day: Higher GH output but significantly increased appetite and water retention. Not recommended unless you have experience with Ibutamoren

Timing

RAD 140: Take in the morning with food. The half-life is approximately 60 hours, so timing is flexible, but morning dosing keeps things consistent. For general dosing principles, see our guide on how to take SARMs.

MK 677: Opinions vary. Some users prefer evening dosing to enhance sleep quality and minimize daytime lethargy. Others prefer morning dosing to capitalize on the appetite increase for bulking. I take mine before bed and find the sleep benefits more valuable than the appetite timing.

Cycle Structure

A standard 8-week beginner cycle looks like this:

Week	RAD 140	MK 677	Notes
1-2	10mg/day	15mg/day	Assess tolerance
3-8	10-15mg/day	15-20mg/day	Increase only if well-tolerated
9-12	Off	Optional: continue at 15mg/day	PCT begins for RAD 140

MK 677 does not cause hormonal suppression, so it can be continued through PCT or run as a standalone after the RAD 140 portion ends. This is actually one of the advantages of this stack; the MK 677 bridges the recovery period and helps maintain the gains while your natural testosterone comes back online.

RAD 140 and MK 677 Side Effects and How to Manage Them

Both compounds carry real side effects. Pretending otherwise does a disservice to anyone considering this stack. Here is what to watch for and how to handle it.

RAD 140 Side Effects

Testosterone suppression. This is the most significant rad 140 side effect. RAD 140 suppresses natural testosterone production in a dose-dependent manner. At 10mg, suppression is moderate. At 20mg for 10+ weeks, it can be substantial. Symptoms include decreased libido, fatigue, and mood changes toward the end of a cycle.

Management: PCT is non-negotiable. More on this below.

Liver enzyme elevation. Some users see elevated ALT and AST levels during a rad 140 cycle. Case reports in the literature have documented liver injury associated with SARMs including RAD 140. Do not stack with alcohol or other hepatotoxic substances. Get liver panels checked before and during your cycle.

Lipid changes. RAD 140 can suppress HDL and elevate LDL. This is usually temporary and resolves after the cycle, but it is worth monitoring if you have pre-existing lipid concerns.

Hair shedding. Some users report temporary hair thinning. This appears to be less common than with anabolic steroids, but it happens.

MK 677 Side Effects

Increased appetite. This is the most common mk 677 side effect and it can be intense, especially in the first few weeks. If you are cutting, MK 677 may not be the best choice.

Water retention. MK 677 causes water retention and some bloating in many users. This is cosmetic and resolves when you stop, but it can mask visual progress.

Blood sugar elevation. MK 677 can increase fasting blood glucose and reduce insulin sensitivity. Research has shown that Ibutamoren can impair glucose tolerance in some individuals. Monitor fasting glucose, especially on longer runs. If you have pre-existing insulin resistance or diabetes risk factors, this compound needs careful consideration.

Lethargy. Some users experience drowsiness, particularly at higher doses. This is why many prefer evening dosing.

Numbness and tingling. Occasional reports of numbness in the hands (similar to carpal tunnel symptoms), likely related to GH-induced fluid retention. Usually resolves with dose reduction.

Stack-Specific Concerns

Running both compounds together does not create new side effects, but it does mean managing two sets simultaneously. The main practical concern is that MK 677’s water retention can mask the lean gains from RAD 140. Do not panic if you look softer during the cycle; the water drops off quickly after MK 677 is discontinued.

PCT After a RAD 140 and MK 677 Cycle

RAD 140 suppresses natural testosterone production. MK 677 does not. This means your PCT protocol is focused entirely on recovering from the RAD 140 component.

Do You Need PCT?

Yes. Unless you are planning to blast and cruise on SARMs (which I would not recommend), post-cycle therapy after RAD 140 is necessary to restart natural testosterone production and maintain the gains you built.

Some online sources will tell you that SARMs are “mild enough” to skip PCT. This is bad advice. RAD 140 at 10-20mg for 8+ weeks will suppress your hormones. Running without PCT risks extended low testosterone symptoms, muscle loss, fat gain, and a miserable few months.

Recommended RAD 140 PCT Protocol

Compound	Dosage	Duration	Timing
Nolvadex (Tamoxifen)	20mg/day for 2 weeks, then 10mg/day for 2 weeks	4 weeks	Begin the day after your last RAD 140 dose

Alternative: Clomid (Clomiphene) at 25mg/day for 4 weeks. Some users prefer Clomid, but it tends to have more side effects (mood swings, vision changes) than Nolvadex.

For detailed PCT for SARMs protocols, including bloodwork timing and when to adjust, see our complete guide.

MK 677 During PCT

One advantage of this stack: you can continue MK 677 through your PCT period. Since Ibutamoren does not cause hormonal suppression, running it at 15mg/day during PCT helps maintain the GH and IGF-1 elevation that supports recovery, sleep quality, and muscle retention while your testosterone comes back online.

RAD 140 and MK 677 Stack vs. Other SARM Stacks

This is not the only sarms stack worth considering. How does it compare?

RAD 140 + MK 677 vs. LGD 4033 + MK 677

LGD 4033 (Ligandrol) is another popular SARM for bulking. Compared to RAD 140, LGD 4033 tends to produce more water retention and slightly more raw mass, while RAD 140 produces leaner, drier gains. The LGD 4033 + MK 677 stack is better for pure mass-gaining cycles where you are less concerned about water weight. The RAD 140 + MK 677 stack is better for lean bulking and recomposition.

RAD 140 + MK 677 vs. RAD 140 + Cardarine

Stacking RAD 140 with Cardarine (GW-501516) instead of MK 677 shifts the stack toward cutting and endurance. Cardarine enhances fat oxidation and endurance without GH elevation or appetite increase. If your goal is fat loss while preserving muscle, RAD 140 + Cardarine is the better choice. If your goal is lean mass gain with enhanced recovery, RAD 140 + MK 677 wins.

RAD 140 + MK 677 vs. Testosterone Cycle

A basic testosterone cycle (300-500mg weekly) will produce more dramatic muscle gains than any SARM stack. However, injectable testosterone comes with more complex side effect management (aromatization, hematocrit elevation, injection logistics) and requires a more involved PCT. The RAD 140 + MK 677 stack is simpler to run, oral-only, and produces moderate but meaningful results. For users not ready to commit to injectables, this stack is a reasonable middle ground.

Tips for Maximizing Your RAD 140 MK 677 Stack Results

The stack does the heavy lifting pharmacologically, but your results still depend on what you do outside the lab.

Training

Run a structured resistance training program focused on progressive overload. This is not the time for random workouts. Compound movements (squats, deadlifts, bench press, rows, overhead press) should form the foundation. Train 4-5 days per week with adequate volume. The enhanced recovery from this stack means you can push harder, but that only matters if you are actually pushing.

Nutrition

You need a caloric surplus to build muscle. Aim for 300-500 calories above maintenance. Protein intake should be at minimum 1g per pound of body weight. MK 677’s appetite boost makes this easier, but make sure those extra calories come from quality sources, not junk food.

Blood Work

Get a pre-cycle blood panel that includes total testosterone, free testosterone, LH, FSH, liver enzymes (ALT, AST), lipid panel (HDL, LDL, triglycerides), fasting glucose, and IGF-1 if possible. Repeat mid-cycle (week 4-6) and again 4-6 weeks post-PCT to confirm recovery.

Sleep

MK 677 will likely improve your sleep, but do not rely on the compound alone. Aim for 7-9 hours per night. Good sleep hygiene amplifies the GH release that MK 677 facilitates.

Hydration

Drink more water than you think you need. Both compounds can affect fluid balance. Staying well-hydrated helps manage MK 677’s water retention and supports kidney function during any supplement or compound use.

The Bottom Line on the RAD 140 MK 677 Stack

The RAD 140 MK 677 stack is one of the most popular SARM combinations for a reason: it pairs direct muscle-building action (Testolone) with systemic recovery and GH support (Ibutamoren) in a way that produces results beyond what either compound delivers alone. As a SARMs stack for bulking, it remains one of the best sarms stacks available.

It is not without trade-offs. RAD 140 will suppress your testosterone and stress your liver. MK 677 will make you hungry, bloated, and potentially insulin-resistant. These are manageable side effects for most healthy individuals, but they require monitoring and responsible use.

If you run this stack at sensible doses (10-20mg RAD 140, 15-25mg MK 677) for a reasonable duration (8-12 weeks), follow it with proper PCT, and support it with solid training and nutrition, you can expect meaningful lean mass gains, better recovery, and improved body composition. Just do not expect steroid-level results from the RAD 140 MK 677 stack, and you will not be disappointed.