Ostarine on testosterone as a natural athlete

Is Ostarine safe for a natural guy?

In this article, we’re going to talk about Ostarine. Is it safe, how effective it is, whether it’s suppressive, is it worth it, etc.

Hans here! I increased my testosterone to 1254ng/dl and have been maintaining high T naturally. I’ve turned myself into an Alpha Energy Male.

An Alpha Energy Male with high energy, fast recovery, high sex drive, and confidence.

This is why I research obsessively, experiment and write, and have been doing so for the past decade.

Hope you enjoy and join me on this journey.

What we’re going to discuss

Ostarine and Anderine basics

Ostarine, aka Enobosarm or MK-2866 and Anderine (S4), are SARMs (selective androgen receptor modulators). This means that it activates the androgen receptors, similar to hormones like testosterone, DHT, etc.

However, Ostarine and Anderine are non-steroidal SARM without androgenic effects. Meaning it doesn’t/shouldn’t cause hair loss, affect prostate size, sebum production (leading to acne), deepen the voice or lower LH.

Basically all the benefits of steroids without the side effects.

Ostarine and Anderine are among the first nonsteroidal SARMs developed by GTx and Merch & Co (R). Due to their anabolic effects, SARMs are also potential performance-enhancing agents in sports, and their misuse in and out of competition is prohibited since 2008.

Anderine has 95% bioavailability at 1-10mg/kg in rats. This decreased to 57% at doses of 30mg/kg. The half-life of Anderine is about 2.6-5.3h in animals (R).

Ostarine is said to have a half-life of 24 hours in humans (R). However, even 1mcg was still detectable in the urine after 9 days (R).

How SARMs work

There are 2 main hypotheses on how SARMs work (since both steroids and SARMs work on the AR, but with differences) include:

  1. Hypothesis 1 (coactivator hypothesis): This hypothesis presumes that testosterone-bound AR and SARM-bound AR have different coregulator proteins, which leads to transcriptional activation of a differentially regulated collection of genes (R).
    • Meaning, SARMs, and androgens regulate genes differently despite acting on the same receptor.
  2. Hypothesis 2: This hypothesis assumes that distinctive ligand classes have unique thermodynamic partitioning and are expressed into conformationally different states. The conformational modifications in the ligand-binding domain are induced by the ligand binding and might change surface topology, thus modifying protein-protein interactions between AR and other coregulators (R). I don’t know about you, but that makes little sense to me. Moving on.

A few little know possible actions of Ostarine include. Ostarine:

  • Might help with antibiotic resistance (R).
  • Likely doesn’t cross the blood–brain barrier (BBB) (R). However, since it does lower LH in high doses, it likely does cross the BBB for some people.
  • Modulate the following receptors/pathways:
    • Melanin-concentrating hormone receptor 2 (MCH-1 & 2) – MCH may play a role in the homeostasis of energy.
    • Prostaglandin E synthase (PGES) – PGES converts the cyclooxygenase-2-derived prostaglandin E2 H2 (PGH2) into prostaglandin E2 (PGE2) and has been implicated in inflammation and cancer
    • Protein farnesyltransferase/geranylgeranyltransferase type I alpha subunit (FNTA)
    • C-X-C chemokine receptor type 3 (CXCR3)
    • Mineralocorticoid receptor
    • Sphingosine 1-phosphate receptor Edg-1
    • Cathepsin S
    • Estrogen-related receptor alpha

I know most of this info has zero relevance for this article, but it’s still fun to insert here.

Benefits of Ostarine

Based on the available human studies out there, Ostarine:

  • At doses of 1 to 3mg daily increased muscle mass and muscle function (strength, power, functionality, etc.) in the elderly (R).
  • Caused a 41.3% reduction in insulin resistance at 3mg (R).
  • Doesn’t influence LH, sebum, hair follicles or PSA at 1 or 3mg (R, R).
  • Is anabolic to bone and can help to prevent osteoporosis (R).

What also makes it attractive to users is the fact that it can be taken orally (no injection required) and it’s likely not as harmful to the liver as other oral steroids.

Side effects of SARMs

The FDA has warned that SARMs can have serious side effects ranging from risk of heart attack to stroke and liver damage (R). Obviously in a dose-dependent manner.

In the trials where they used 1-3mg daily, some people had small elevations in liver enzymes, but nothing severe (R).

There are a few case reports of people who got much more severe side effects from higher doses.

Case report 1

A previously healthy man in his early 40s presented with new-onset jaundice, anorexia, weight loss, fatigue, and diarrhea.

He was taking Ostarine for weight training and muscle gain for 2 months before going to the ER.

Although he only had very little liver damage, his symptoms were due to drug-induced cholestatic liver injury (R). Meaning, the body was unable to excrete bile acids (backup of bile), which caused liver damage.

Case report 2

A 43-year-old male, sports coach, presented himself at the Emergency unit of a local hospital for epigastric pain, myalgia pain and severe headache.

He used a combination of Ostarine with cardenine which caused severe liver issues. He has very elevated liver enzymes ALT (up to 922 UI/L) and AST (up to 2558 UI/L). He also had massive rhabdomyolysis with elevated creatine phosphokinase (CPK) (up to 86435 UI/L) (R). He recovered completely in 6 weeks. You can expect that he didn’t retain any of his gains.

Suppression risk of Ostarine

One of the reasons why Ostarine was designed in the first place was to prevent suppression; a major downside of other steroids.

At 1 or 3mg daily, Ostarine didn’t lower LH in the elderly.

However, higher doses haven’t been officially studied. But there are a lot of anecdotes.

Reddit reviews

I started with 15mg then went up to 25mg over 8 week cycle and I felt quite suppressed at the end but my LH and FSH were fine so I didn’t PCT and fully recovered naturally (R).

Lmao Ostarine is DEFINITELY suppressive. I feel absolutely horrible near the end and when it’s over even with pct. I’ve never seen anyone’s blood work be anything less than 60% suppression of total T on osta, and that’s being generous. It’s usually a lot more. For The blood work ive seen at 800ng/dl, it goes down to 100ng/ 300ng/dl. (R)

Hey, so I ran an Ostarine cycle for a month like an idiot. Starting at 15mg first week, 30mg for 2nd and 3rd week, and around 40mg for 4th week. I fucked up and was given the wrong advice on how to run the cycle. My test dropped from 861 to 360. (R)

At 15mg for 4 weeks, 20-25mg for another 4 weeks. I saw suppression from week 6 and onwards, I did an 8-week cycle in total. Saw noticeable ball shrinkage but otherwise everything was fine. (R)

Usually 3-4 weeks but it totally depends on the person. You might not be suppressed at all. I ran Osta 20mg for 8 weeks and wasn’t suppressed in the slightest.

A 9-week MK-2866 bulking cycle put my T from the 500s ng/dL precycle to ~80 ng/dL at the end of the cycle with significant LH suppression. (R)

4 weeks and half, 12.5mg/Day, in normocaloric/minibulk put my T from 494ng/dL to 326ng/dL. (R)

Day before starting cycle:Testosterone, Total: 579ng/dL Testosterone, Free: 85.6pg/mL. Last day of 12wk cycle: Testosterone, Total: 79ng/dL, FSH: 5.3 mIU/mL, LH: 3.2 mIU/mL. On 20mg for 12 weeks. (R)

Everyone responds differently to the drug. But I’d say that it’s best to assume that you will get suppressed. Also, do bloods before and after to see how significant the changes were.

Because if you only test afterward you might find out that your T is 400ng/dl, but might not know that it was 400ng/dl before even starting Ostarine.

Symptoms of suppression

As some guys have said, they had symptoms of suppression, yet their LH and FSH were normal. It could be that Ostarine inhibits testicular testosterone production independent of LH.

Suppression symptoms:

  • Tired
  • Lethargic
  • Low sex drive
  • Low motivation
  • Low mood
  • Depression

Ostarine and Andarine are the least suppressive drugs, whereas YK11 and S23 are the most suppressive (because they’re more powerful).

Other “SARMs” that’re not suppressive

Other wrongly categorized SARMs such as MK-677, Cardarine and Stenabolic are non-hormonal and are not suppressive.

Will Clomid or Enclomiphene help to prevent suppression from SARMs?

No, since SARMs bind to the AR and don’t convert to estrogen. Plus, if SARMS drops T, E2 will also drop. SERMs like Clomid block the ER, thus it will be non-effective when used to prevent suppression. The only thing that will help is HCG as it directly stimulates the testes to produce T.

If you have low T prior to SARMs, you’ll have low T after SARMs. It’s not that you’re still suppressed, it’s that you still have low T, to begin with.

SERMs are even sometimes used as an alternative to TRT. Some doctors like to use Clomid or enclomiphene as a first option treatment for low testosterone before prescribing injections/topicals (but only if the patient also has low LH).

You can buy enclomiphene here in the US:

And here in the UK:

Natural PCT

Is it possible to do a natural PCT?

Natural compounds will not be as potent as synthetic drugs, but they can definitely be helpful. A few good ones include:

  • Damiana (inhibit aromatase)
  • Aspartic acid (stimulate LH release)
  • Longdan Xiegan Tang is a natural alternative to Clomid. One of the ingredients blocks the estrogen receptor in the pituitary and can help increase LH and thus testosterone.

How long to PCT?

The standard duration to do a PCT for is 3-4 weeks. But Ostarine is out of your system in 7-10 days, which means there will no longer be any suppression. So even a 2 week PCT might be enough. Some guys don’t get a drop in LH from Ostarine and won’t benefit from SERMs.


Most people use Ostarine as a “safe” anabolic to boost muscle gains. The supposed upside is that it won’t cause suppression. But it does in a lot of people.

The biggest upside is that you don’t have to inject yourself, but the downside is that these are synthetic compounds with very little research behind them. This means that we have no idea all the effects/side effects they might have.

Another upside is that any suppression is likely short-term due to the relatively short-ish half-life of the compound.

The liver damage and cholestasis can be mostly prevented by taking TUDCA with Ostarine at the same time.

Is SARMs really worth it? Ostarine will likely not give you any “steroid” like gains/results, which is why people use SARMs in the first place. It’s all about setting the right expectations. Do you want steroid-like gains? Perhaps using steroids would be more conducive to that goal. if you just want a little more muscle gain and faster recovery, maybe these SARMs can help you out.

>1000ng/dl Testosterone: My Step-by-Step Guide on How I Do It Naturally!

4 thoughts on “Ostarine on testosterone as a natural athlete”

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: