Disclaimer: Individuals should only use SARMs for research purposes, as they are not FDA-approved and may have adverse effects. Dr. Touliatos is available for consultation should readers have any questions or concerns.
Ostarine is a selective androgen modulator receptor (SARM), and Cardarine is a peroxisome proliferator activated receptor delta (PPARD) agonist. Both substances are utilized by weightlifters to stimulate anabolism and lipolysis.
For men, an Ostarine and Cardarine stack is commonly administered during a cutting phase, with Ostarine producing mild increases in muscle hypertrophy, up to 10 pounds.
Women may also use this stack to enhance fat reduction. However, Ostarine is an effective muscle builder for females, with novices often adding up to 20 pounds of fat-free mass from a cycle.
Ostarine and Cardarine Stack Dosage
For Men
Moderate Cycle:
- Weeks 1–8: Ostarine 15 mg/day, Cardarine 10 mg/day
Aggressive Cycle:
- Weeks 1–8: Ostarine 20 mg/day, Cardarine 20 mg/day
- Weeks 9–12: Cardarine 20 mg/day
For Women
Moderate Cycle:
- Weeks 1–8: Ostarine 10 mg/day, Cardarine 10 mg/day
- Weeks 9–12: Cardarine 10 mg/day
In our experience, Ostarine does not cause virilization side effects in women when administering moderate dosages, such as 10 mg/day or less.
Disclosure: We do not accept any form of advertising on Inside Bodybuilding. We monetize our practice via doctor consultations and carefully chosen supplement recommendations, which have given our patients excellent results.
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Ostarine and Cardarine Stack Results
The above user published his results on Reddit, where he reported losing 20 pounds after an 8-week cycle consisting of 10 mg/day of Cardarine and 20 mg/day of Ostarine.
A male Facebook user also shared his progress from this stack.
After 8 weeks on Ostarine/Cardarine cycle, 25 pounds of fat lost and about 10 pounds of muscle added. I stuck to my diet and worked my butt off in the weight room. Gonna crush it with RAD 150 in the fall!
Below are further before and after transformations after Ostarine-only and Cardarine-only cycles. This allows researchers to estimate the potential for results when combining the two substances.
Ostarine Results
The outcomes from an Ostarine and Cardarine stack will be more notable than those from individual cycles. Consequently, users can anticipate more prominent fat reduction relative to the images below; nevertheless, no additional muscle development will occur since Cardarine is not anabolic.
The combination of Ostarine with a modest caloric deficit can provide significant fat reduction, as shown by the following Reddit user who consumed 20 mg daily for 45 days.
- This individual decreased his total bodyweight by 3 kg (7 lbs) while increasing his lean body mass.
- Consequently, the outcomes can be excellent when Ostarine is integrated with consistent weight training and a rigorous diet.
Cardarine Results
The before and after picture illustrated below details a Reddit user’s results following a 12-week Cardarine cycle.
- This user’s bodyweight decreased by 40 pounds.
- During the first week, he consumed 10 mg/day, followed by 20 mg/day for the remaining 11 weeks.
Consequently, the concurrent use of Ostarine and Cardarine has significant impacts on body composition, including:
- Subcutaneous and visceral adipose tissue reductions
- Moderate hypertrophic muscle development
For women, the muscle gains from Ostarine and Cardarine will be comparable to the level of fat loss, resulting in a significantly lower body fat percentage and substantially larger musculature.
We have found Ostarine and Cardarine to be among the most powerful PED stacks for rapidly transforming a woman’s body composition.
Cardarine also has a profound effect on muscular endurance. Therefore, athletes or those performing regular cardiovascular exercise often experience vast improvements in their maximal oxygen uptake (VO2 max).
Ostarine and Cardarine Side Effects
Our tests suggest that Ostarine and Cardarine are generally well-tolerated compounds and do not typically cause excessive adverse effects in either men or women. However, users should be cautious of the following side effects:
Testosterone Suppression
It has been established in our SHBG testing that Ostarine stimulates AR (androgen receptors), which results in a reduction of endogenous testosterone.
Some Ostarine users do not experience any obvious low testosterone symptoms in regard to mood, sex drive, and energy. However, these same individuals can exhibit 60–70% reductions in total testosterone following bloodwork analysis. Such decreases may be ascribed to free testosterone levels remaining within a normal range while total testosterone levels decline. This is not inherently harmful since free testosterone is the essential metric due to it being active and unbound.
We find testosterone levels typically recover several weeks after cycle cessation. For researchers who observe harsh testosterone suppression from Ostarine, they may administer a post-cycle therapy, such as Nolvadex or Clomid, to accelerate hypothalamic-pituitary-testicular axis (HPTA) recovery.
Liver Toxicity
Our anecdotal data suggests that Ostarine may elevate alanine transaminase (ALT) levels by 30% over the maximum typical range. This signifies moderate amounts of hepatotoxicity. To inhibit hepatic stress, the following supplements may be taken:
- Tauroursodeoxycholic acid (TUDCA)
- Silymarin (milk thistle)
- N-acetyl cysteine (NAC)
In Dr. Thomas O’Connor’s experience with patients on Cardarine, he concludes that it is “hepatotoxic,” and “more so than some anabolic steroids.”
Dr. O’Connor likens a standard Cardarine dose to causing “the same hepatic stress as a high dose of Anavar.”
Consequently, both men and women must exercise caution while combining Cardarine with Ostarine, since this combination will undoubtedly exert stress on the liver. By monitoring ALT and aspartate transferase (AST) levels during a cycle, users can more accurately calculate tolerable dosages.
The liver is a robust and resilient organ; thus most individuals should have no difficulties with this stack. Nevertheless, those with compromised hepatic health should refrain from utilizing this cycle.
Blood Pressure
Ostarine, despite its reputation as a benign SARM, has the potential to induce moderate blood pressure fluctuations.
We have seen Ostarine decrease high-density lipoprotein (HDL) cholesterol by 30% on mild dosages of 3 mg/day for 12 weeks. Research also indicates that blood lipids may be negatively affected by Ostarine in the short term (1).
Carcinogenic
A 2009 study found that administering large amounts of cardarine for extended periods of time can induce cancer proliferation in rodents (2). The rodents were given 5 mg/kg per day for 3 years, which translates to 65 mg/day for an 80 kg human.
However, this protocol is incomparable to the common doses that humans will take for cosmetic purposes, being 10–20 mg per day for a period of 3 months.
In order to more accurately evaluate the potential dangers of cardarine-induced cancer proliferation, additional research on humans is required.
How to Take Ostarine and Cardarine
Ostarine and Cardarine are not FDA-approved compounds, and thus there is no established dosage guideline for men or women.
Typically, we administer ostarine orally at a concentration of 25 mg/mL.
For optimal bioavailability, users commonly let the liquid remain under the tongue for 15 seconds. This sublingual delivery method enhances bioavailability by enabling a more direct route into the bloodstream.
Ostarine has a half-life of 24 hours; thus, one dose per day is required.
Ostarine’s fast-acting nature allows for its use one hour before exercise. In such an instance, users may observe enhancements in:
- Musclular strength
- Aggression
- Energy levels
- Motivation
Similar to Ostarine, people frequently acquire Cardarine in liquid solution form (20 mg/mL) and administer it orally. Nevertheless, Cardarine is a stimulant to the central nervous system (CNS), so it may be beneficial for consumers to take their doses earlier in the day to prevent insomnia.
Given that Cardarine has a half-life of 16 hours, one dose per day is also acceptable.
Conclusion
An Ostarine and Cardarine stack is a potent fat-burning combination.
However, men are unlikely to build significant amounts of muscle hypertrophy on this stack, especially if adopting a calorie deficit diet. However, we have seen women build large amounts of lean muscle on Ostarine and Cardarine, in conjunction with dramatic fat loss (3).
The risks of Ostarine and Cardarine appear to be mild in the short term. However, further human research is necessary to fully understand the safety of both of these drugs before reaching definitive conclusions.