S4 (Andarine) or Acetamidoxolutamide, is a SARM (Selective Androgen Receptor Modulator). But the idea for S-4 didn’t start out as many believe.

It wasn’t an attempt to create a safer version of steroids or any of that nonsense people use to sell anabolics.

S-4 started out as a new development for male contraceptives and showed promising results like decreases in spermatogenesis and huge boosts in male libido. For any of you who have had trouble getting your wife pregnant while on sarms…you’re welcome.

However, when researchers began experimenting on mice with S4, they discovered interesting findings of how this first generation SARM affected castrated lab mice.

Not only did Andarine increase the production of muscle mass and calcium for bone density, but was COMPLETELY SELECTIVE in its tissue growth!

As studies continued, many of these research trials resulted in astonishing outcomes creating a benchmark for even more research.

Today, we’ll take a closer look at everything we currently know in 2018 about Andarine in this write-up…

How Andarine (S4) Works

To start, let’s describe what a SARM does.

There are three type of chemicals that act on the androgen receptor (AR):

• 1st is the AR antagonist, which is a chemical that binds to the receptor to prevent it from activating.
• 2nd is an AR agonist, which binds to the receptor and detaches, then binds again, over and over.
• 3rd is an AR modulator, or basically a molecule that attaches to an AR and changes its structure to react however it wants.

A SARM such as S-4 is a good example. S-4 attaches to the AR and sticks to it; each time the AR interacts with testosterone, S-4 forces it to produce genes that exclusively benefit muscle and bone growth. In other words, S4 is a form of SARM that attaches to the androgen receptor (AR) the same with regular androgens, the only variation is that S4 generates selective anabolic activity.

As mentioned earlier, SARMS function by tying to the AR resulting to anabolic activity. Due to this fastening and stimulation, more protein is produced which allows muscle building. S4 can trigger muscle development in the same way as steroids, but minus the same unwanted side effects.

S4 is a SARM with utmost androgenic effects and is 33% of the strength of testosterone when attaching to AR.

S-4 also increases the amount of muscle mass produced by desensitizing the AR to the individual’s natural testosterone to influence a stronger effect.

The Key Benefits of S4 (Andarine)

S-4 is by far the most versatile SARM ever created. Not only is it the first SARM approved for a stage 2 research study, but it has also become the most analyzed and investigated SARM so far. After the discovery of its anabolic potential, the primary purpose of S-4 aimed to develop an alternative treatment to age-related muscle wasting, osteoporosis, and similar symptoms of hypogonadism, or end-stage renal disease.

Aside from preserving lean body mass, S4 can also help improve it.

From a stage 1 study, S-4 has provided evidence of a 3.3 lbs increase in less than 90 days with no increases exercise or change in daily diet. An unintended side effect (or benefit if you will) is the decrease in body fat [Chen et al., 2005; Gao et al., 2005; Kearbey et al., 2007]. Decreases in body fat are dependent on the person’s genetics, but it will definitely have strong effects on the body’s ability to oxidize fatty tissue. S-4 was found to not only have a great affinity (potency in binding to androgen receptors), while also presenting greater anabolic effects than some traditional steroids [Kearbey et al., 2007].

Aside from its muscle building advantages, S4 won’t cause liver damage, can prevent gynecomastia (enlarged breasts in men) and can help boost your overall health.

Here are some of the other benefits of Andarine that are worth noting:

• Very minimal growth on secondary sexual organs such as the prostate.
• The LDL/ HDL ratio is not affected which makes it a low cardiovascular risk.
• 0% chance of aromatization, male breast lactation, or rise in any other female characteristics during the post cycle recovery. [Kearbey et al., 2007]
• Testosterone is not diminished in any capacity during the post cycle recovery.
• Very exclusive in tissue selection and growth which means it will not cause heart enlargement or damage to neighboring organs.
• SARMs do NOT require the utilization or devouring of liver enzymes to activate their anabolic effects. This eliminates any risk of hepatotoxicity or hepatitis.
• Although SARMs such as S-4 are not as powerful as comparable steroids such as Winstrol, they do not require the extensive post cycle therapy and can be cycled back to back throughout the year. Over the course of a year, obtaining the same results is very possible.
• SARMs is very female friendly and does not cause excessive masculine features such as enlarged sexual characteristics.
• S-4 has overall presented larger increases in muscle mass than DHT.

Full Muscle Regeneration & Lean Body Mass

Once more, an early study done on S-4 provided proof of full muscle regeneration in volunteers with degenerative disorders without the use of exercise and the minimum dosage of 3mg/kg/day. Changes can be seen anywhere from 1-2 weeks. This was the very first study classified S-4 as CLINICALLY SIGNIFICANT by improving skeletal muscle strength, lean body mass, and a reduction in body fat [Chen et al., 2005; Gao et al., 2005; Kearbey et al., 2007]. Unfortunately, there are always some side effects that arise when using Because S-4 is a ligand by definition, the side effects will never be permanent even at supra-physiological dosages and can be easily avoided through proper dosing.

The Side Effects: What You “See” Is What You Get

Unfortunately, there are always some side effects that arise when using Because S-4 is a ligand by definition, the side effects will never be permanent even at supraphysiological dosages and can be easily avoided through proper dosing. Also, Andarine follows the law of diminishing returns meaning that over time, your body will develop a tolerance and the SARM will become less effective after a certain milligram percentage. For the average person, it ranges from 50mg to 75mg. there are people that can go above this range for even more amazing results or need to stay below this range because they are unable to tolerate the chemical. About 99.5% of the population should fall within the 50mg to a 75mg range.

The most popular negative effects of S-4 are visual issues such as the yellow tint and difficulty adjusting to night vision. These side effects are unique to S-4 and are sometimes overblown. If these side effects present themselves, simply stop taking S-4 for two days and stay at a 5 day on/ 2 day off cycle. THESE EFFECTS ARE NOT PERMANENT! Once a ligand (such as a SARM) leaves the system, its effects disappear completely.

Lastly, S-4 and most other SARMs have been known to cause depression in a small population of people. This has been discovered as more of a psychological issue than a physiological issue. researchers with mice suffering from any emotional disorders need to be cautious when using this chemical.

Andarine Dosing Guidelines

Benefits of Andarine have been reported with dosages ranging between 25mg and 50mg 3x per day.

Unfortunately, the higher the dosage, the higher the side effects. S4 is a rare form of SARM that has a greater risk of side effects than most other SARMs.

These effects are not permanent. S4 has been proven safe and effective for cycles up to 3 months.

More Dosing Guidelines

One study in particular compared S-4 to DHT (a common anabolic steroid); the results have shown that S-4 exceeded DHT in producing lean muscle mass over the course of 120 days with only 3mg per day. Another study identified that S-4 is completely absorbed even at very low doses.

Here are some more general guidelines depending on goals:

• Most people have opted to split their 50mg to 75mg doses into 3 separate doses (one with each meal), 5 days per week for no more than 12 to 16 weeks. This has become somewhat of a dogma but there are now studies proving that it is any more effective than one solid dose once a day [Chen et al., 2005a; Gao et al., 2004; Gao et al., 2005; Kearbey et al., 2007; Kearbey et al., 2004].
• Once again, as mentioned above, S-4 does have a point of diminishing returns. This means usage of S-4 passed 75mg or usage of S-4 for more than 16 weeks will not result in any added muscle mass. There will not be an increase in side effects either, but you will be running the risk of AR desensitization and inevitably wasting your product.
• Dosing with S-4 for less than 6-8 weeks is not recommended and will not allow the researcher to witness the full benefits of the product.

The recommended dose for cutting is 50 mg for 6-8 weeks. You should use it every day then take 2 days off for the duration. Taking S4 daily for the length of the cycle can lead to changes in eyesight.

Uses of Andarine

For Cutting (best use of S4)

Andarine’s properties are very alike with steroids Anavar and Winstrol, the only difference is that S4 can better provide lean muscle gains. In fact, there have been many cases of bodybuilders gaining up to 3 pounds of lean muscle while on a caloric deficit! S4 displays the same binding resemblance to AR, hence presenting similar fat burning effects. S4 can also minimize LPL (lipoprotein lipase) – an enzyme that causes lipid accumulation and plays a role in storing adipose tissue (excess body fat). The AR oxidizes this adipose tissue and uses it as its preferred energy source, allowing the body to decrease excess fat at an amazing rate.

It also improves vascularity for that “aesthetic” chiseled look with minimal to no water retention. Unlike steroids, it won’t affect your joints but reinforce muscle mass and power instead. You can also say goodbye to painful pumps.

Recommended Dosage: 50 mg for 6-8 weeks.

*Take 2 days off when taking S4 (repeat the cycle after the 2-day break) to avoid vision side effects.

For Recomping

Use S4 with a more anabolic SARM such as Ostarine for better re-comp results as you’re aiming to gain muscle while losing fat. Recommended intake is 50-75 mg for 4 to 8 weeks.

For Bulking

S-4 isn’t the SARM that comes to mind when we think “BULKING”, but it’s properties in muscle gain shouldn’t be overlooked. During the holiday season, many people take advantage of the excess food and snacks available and jump on some well known bulking SARMs such as LGD 4033 or RAD 140. While there isn’t an enormous 15 lb leap in muscle like these “bulk specific” products, S-4 can provide relatively large muscle gains and utilize these excess calories to provide an extra 8-10 lbs in muscle while also keeping the body relatively lean. This steady increase in muscle mass can limit the amount of work one needs to do for a leaner summer body.