SARMs Side Effects [Guide]

sarms side effects

SARMs side effects – are they cause for concern like everyone makes SARMs out to be?

A cursory Google search yields plenty of sensationalized fear, but a lot of Reddit and forum advocates proclaim SARMs as the best alternative to testosterone therapy. 

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While steroids like testosterone are well known to promote muscle growth, they also come with a myriad of physiological changes that need to be managed. They can shut down natural production of testosterone depending on the length of use. 

SARMs function a little differently, by selectively interacting with tissue, namely muscle and bone. While they will still lead to testosterone, LH, and FSH suppression – it is reversible and not permanent like the testicular atrophy one may see with prolonged steroid use. 

SARMs – What Are They?

Perhaps misleadingly referred to as “gray market research chemicals,” SARMs have gotten quite a bad rep since their rise to popularity as an alternative to testosterone injections. 

SARM stands for Selective Androgen Receptor Modulator and like most Androgenic compounds can cause SARMs side effects. 

More specifically, SARMs are a class of “androgen receptor ligands,” which bind to androgen receptors and promote tissue-selective androgenic signaling. 

They were originally developed as steroids in the 1940s based on modifying the testosterone molecule, while we are now in an era of “nonsteroidal SARMs.” 

These compounds are similar to androgenic steroids and are not “approved for use” or regulated by the FDA. Regardless, SARMs are available to purchase through various online health stores, supplement stores, bodybuilding stores, and companies within the United States. 

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SARMs are heavily promoted online within certain bodybuilding communities as a way to help build muscle without the “dangers” associated with traditional steroid injections of testosterone. 

Even in clinical studies, SARMs have shown promise as a tool to help build lean mass and contribute to enhanced muscle strength

They do not appear to have the same SARMs side effects on the reproductive system for men and women that traditional steroids do. Studies report “improved physical function without [adverse] effect to the prostate and cardiovascular [system].”

That being said, many men do still experience symptoms of testosterone suppression while on a cycle, along with other sides – we’ll discuss these side effects and the importance of cycling and PCT after SARM side effect use to help prevent this. 

These substances can be used safely, but you need to be educated about them first. 

The Importance of Cycling and PCT After Taking SARMs

Many YouTubers and advocates of SARMs will adhere to strict cycles and mention their use of “PCT.” 

This stands for Post Cycle Therapy and often includes taking medications like Clomid or Nolvadex after a cycle of SARM use. 

There are also ‘natural’ alternatives, like Testogen, which offer formulations containing fenugreek, DAA, and boron to “restore” hormonal balance. These will often provide some benefit (mild LH bump), but not to the degree most people coming off a cycle will need.  

SARMs will suppress testosterone, FSH and LH – this is a well known fact. 

The reason why SARMs are advocated for use over injectable testosterone is because they suppress production, rather than causing a full blown shutdown of your body’s natural production. 

Typically, your body can normally recover within an acceptable or baseline range depending on the length of your SARM cycle and dosage. 

As you increase the dosage, the severity of suppression increases, along with the duration. If you are doing doses of 10mg VK-5211 for a period of 12 weeks, you will likely benefit from doing PCT. 

Going with VK-5211 again as an example, studies demonstrated a return to baseline levels from a 1mg dose (used over 12 weeks) after a month of discontinuing use.

side effects mk 677 sarms

If you do not want to do PCT, you need to cycle using the time on/time off principle. 

This means if you do 8 weeks on a SARM, you need to do 8 weeks off to let your body recover. 

Anyone doing longer cycles of 12 weeks or greater, or using higher doses should be doing some form of PCT to assist in normal recovery. 

DAA (D-Aspartic Acid) is not strong enough to be considered appropriate PCT on its own. It does not provide enough HPTA stimulation to produce more testosterone, and only provides a modest rise in LH and libido. 

You can add it to the end of a SARM cycle, but do not depend on it solely. 

SERMs vs. Exogenous Testosterone – Why SERMs are Better for PCT

Generally, you’ll want to use a real compound that can effectively stimulate HPTA (hypothalamic-pituitary-gonadal axis) – this means SERMs like Clomid. 

avoiding sarms side effects

SERMs are “Selective Estrogen Receptor Modulators” which are synthetic hormonal medications that can act/function as estrogen modulators, which can increase testosterone levels and help to maintain spermatogenesis

Studies clearly demonstrate that SERMs and AIs (aromatase inhibitors) can help reverse low serum testosterone levels and hormonal imbalances associated with the regulation of testosterone and spermatogenesis by acting as estrogen antagonists. 

Oral SERMs do not suppress endogenous gonadotropin secretion, which is always seen with exogenous testosterone therapy. This means, unlike traditional testosterone therapy (which is NOT a good choice for PCT), SERMs do not impact or reduce the size of the testes.  

As the following study states: “due to its anti-estrogen effect on the pituitary, which causes an increase in serum FSH and LH, clomiphene [Clomid] appears to be an ideal product to treat [patients] who [have] both low testosterone levels and subnormal sperm counts.” 

This is provided they have low/normal gonadotropin levels. 

AIs work in a similar manner and have historically been used to treat hypogonadal males as an alternative to testosterone therapy. AIs inhibit the conversion of testosterone to estradiol “peripherally and within the testes.”

Tamoxifen, specifically, has been used for its estrogen-antagonist behavior when it comes to the treatment of male gynecomastia. 

It is important to note that while excess or high levels of estradiol can be harmful to testosterone production and men’s health, low levels can also lead to sexual dysfunction and loss of libido. 

If looking into SERMs, we recommend Enclomiphene for optimal HPTA recovery. However, if your primary concern is gynecomastia, Nolvadex is a good option. 

sarms abs side effects

PCT can include fatigue and lowered motivation while coming off SARMs, so we recommend accounting for that with a healthy diet, training, and rest. 

As long as you don’t abuse SARMs, your HPTA should be able to recover/return to baseline levels without issue. 

Common SARMs and Their Individual SARM Side Effects

LGD-4033 (also known as VK-5211; rebranded to Viking Therapeutics)

Recommended Dose Range: 1mg (study) – 5mg (average). Do not exceed 10mg. 

Previously developed by Ligand Pharmaceuticals, and now under production and development by Viking Therapeutics, VK-5211/LGD-4033 is among the more potent of SARMs. 

VK5211 will suppress testosterone production, that is dose dependent. For example, 1mg dose administered over 28 days reduced FSH and LH by 1 u/L.

Common side effects for VK-5211

Lowered testosterone once suppression starts, acne (prolonged use), headaches, acid reflux. 

MK-2866 (also known as Ostarine

Recommended Dose Range: 3mg (study) – 20mg (average). Do not exceed 50mg. 

Generally found to have a lower incidence of side effects, MK-2866/Ostarine was developed by Merck and is commonly used as a treatment for muscle wasting. This SARM is great for maintaining muscle mass, and is less potent than VK-5211. 

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You will still see testosterone suppression while on longer cycles or higher doses. There is a lower risk of gynecomastia as MK-2866 does not induce aromatisation. 

MK-2866 has been demonstrated in clinical studies to help increase mineral bone density, improve collagen synthesis and repair tendons. 

Common side effects for MK-2866

Lowered testosterone once suppression starts, acne (prolonged use), headaches. 


Recommended Dose Range: 5mg (low) – 10mg (average). Do not exceed 30mg. 

RAD-140 was developed by Radius Health for addressing muscle wasting. RAD is an incredibly potent SARM, especially in comparison to MK-2866. It is much more suppressive, which means it needs to be managed in shorter cycles. RAD is great for gaining lean muscle mass. 

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RAD 140, also known as Testolone, is a non-steroidal selective androgen receptor modulator (SARM). Like other SARMs, it binds to specific androgen receptors and doesn’t cause the full spectrum of androgenic effects as similar substances like anabolic steroids, DHT, or testosterone replacement therapy.

RAD-140 appears to display a more pronounced anabolic effect than testosterone injections, with fewer reported side effects. 

In studies where RAD-140 was paired with testosterone, it reinforced the anabolic effects of testosterone while reducing the androgenic effects of testosterone on the prostate. 

Common side effects for RAD-140

Acne, hair loss, and lowered testosterone as suppression starts. 


Recommended Dose Range: 10mg (low) – 50mg (average). Do not exceed 100mg. 

S-4 was developed by GTx to address muscle wasting. S-4 is less potent than other SARMs in both anabolic benefit, and androgenic sides. 

Structurally, it is most similar to MK-2866. Much troubling is that a reported side for S-4 is recurring vision problems. This includes a yellow tint and impaired night vision. May also worsen floaters. 

There is suppression with S-4 as well, but it is mild and more manageable. S-4 is a good option for lean muscle mass. 

Common side effects for S-4

Acne (prolonged dose), vision problems, difficulty with night vision, and low testosterone once suppression starts. 


Avoid this product. There aren’t a ton of conclusive human studies as of yet, and this myostatin inhibitor leans towards being classified as “gene therapy.” Many people online through forums report strength gains, but there is a higher incidence of adverse sides. 

There are better options for SARMs with minimal sides, and with YK-11, you don’t know the validity of the end product you receive. Spend your money elsewhere for better-researched results.


Recommended Dose Range: 10mg (low) – 25mg (average). Do not exceed 50mg.

Not technically a SARM, MK-677 often gets lumped in together with them as a long-lasting selective agonist of ghrelin receptors, mimicking the GH (growth hormone) stimulating action of the ghrelin hormone. 

MK-677 is quite safe, even for prolonged daily use. 

MK-677 does significantly increase plasma GH levels in human and animal test models. It also causes an increase in appetite and can lead to stimulated body weight gain. 

Sides tend to lower in time, and this can be run indefinitely as a sort of analog to HGH. 

precautions starting sarms

A study indicated a cortisol increase, but it seems like a mild initial spike that dissipates with prolonged use. GH does typically increase insulin resistance, so that has a chance of happening here despite a body fat  % decrease from MK-677. 

Prolactin also seems to increase initially but returns to baseline. 

A protocol is typically recommended of cycling 5 days on, with 2 days off. This is to avoid GH symptoms typically associated with higher levels – such as joint pain. Dosing later in the evening can also help with the appetite increase. 

Common side effects of MK-677

Joint pain, stereotypical increased GH symptoms, increased appetite levels. 

Precautions When Starting SARMs

Most studies appear to suggest minimal negative side effects with SARMs, especially when compared to traditional hormone injections. SARMs also do not aromatize into estradiol. 

Of course, even SARMs are not a silver bullet. They aren’t side effect free. HPTA impacts can lead to hormonal imbalances and cause acne, gyno, and headaches at higher doses/longer durations. 

We recommend doing a full blood work panel prior to beginning any SARM cycle, as well as updated blood work coming off. A full hormone panel should include total testosterone, free testosterone, estradiol, SHBG, DHT, PSA, HCT, FSH, LH, cortisol, insulin, thyroid peroxidase antibodies, AST, ALT, and GGT. 

Provided you cycle properly, and moderate the amount you’re using to reasonable levels as we outlined, you shouldn’t experience tanked testosterone once PCT is started or SARM use is stopped.  

lgd 4033 side effect sarms

You also need to be aware of where to properly purchase SARMs, as companies geared towards selling them as bodybuilding products may be selling you prohormones in disguise. Prohormones are not the same and come with many more risks. 

An example of a bulking cycle might look like this: VK-5211/LGD-4033 at 5mg daily, for 8 weeks + concurrent MK-677 at 25mg daily for 8 weeks. Take 8 weeks off, or a week off followed by Nolvadex at 5mg-10mg a day for 4 weeks instead. 

Avoiding SARMs Side Effects

Stacking SARMs is not advisable, as you risk increasing the risks of suppression, poor lipid profile, liver toxicity, and glucose imbalance aka SARMs side effects. The only recommendation, in this case, is stacking a SARM with something like MK-677 at a very low dose. 

Any advice for a novice SARM user, or personal experience with side effects? Let us know in the comments below. 

Dr. Ian Nellis MD
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Dr. Ian Nellis MD

Dr. Ian Nellis is a medical doctor with over ten years of experience in the health care industry. Dr. Nellis is passionate about sports nutrition and helping his patients live healthy and fulfilling lives. He lives and practices medicine in Denver, CO, with his wife and beloved Mastiff Leonardo.

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