Ostarine vs Cardarine: complete comparison (SARM vs PPARδ, mass vs endurance)
| Critère | ostarine | cardarine |
|---|---|---|
| Class | SARM (androgen receptor) | PPARδ agonist (non-SARM) |
| Main effect | Lean mass, strength | Endurance, lipid oxidation |
| Half-life | ~24 h | ~12-24 h |
| Hepatotoxicity | Moderate | Low reported |
| HPG axis suppression | Moderate | None |
| Typical dose | 15-25 mg/d | 10-20 mg/d |
| Oncologic risk | Low (preclinical) | High (Mitchell 2019) |
| PCT required | Yes (mild) | No |
Quand choisir ostarine
Ostarine (enobosarm, MK-2866) is the most studied SARM in humans: Dalton 2011 (phase 2, 120 elderly patients) demonstrated +1.4 kg lean mass at 3 mg/d × 16 weeks with improvement of functional performance. Choose it for: (1) a first mild SARM cycle, (2) a preservation cycle in deep cut (anti-catabolic effect in caloric deficit), (3) a 'recomp' cycle with modest mass gains and simultaneous fat loss, (4) a complement to an AAS cycle for finish. Favorable pharmacological profile (Solomon 2019, Bhasin 2009): non-steroidal SARM, strong muscular selectivity, no aromatization, moderate HPG suppression even at high dose. Drawbacks to anticipate (Pope 2014): possible ALT/AST elevations (reported in 5-15% of users on 8-week cycles), slightly degraded lipid profile (HDL down), suppression of endogenous testo by 30-50% at 25 mg/d. Typical dose 15-25 mg/d × 8-12 weeks, single morning intake (half-life ~24 h). Mild PCT nolvadex 20 mg/d × 4 weeks suffices in most cases. Acceptable in women at 5-10 mg/d with virilization monitoring.
Quand choisir cardarine
Cardarine (GW-501516) is NOT a SARM but a selective agonist of the PPARδ receptor (peroxisome proliferator-activated receptor delta), entirely different pharmacological class. Narkar 2008 demonstrated in mice a marked endurance increase by activation of mitochondrial metabolic pathways (AMPK, mitochondrial biogenesis, lipid oxidation). Choose it (with extreme caution) for: (1) a cardiovascular endurance cycle (cycling, marathon, long-distance running), (2) improved lipolysis under effort by increased fat oxidation, (3) a complement to an AAS cycle to counterbalance cardiovascular and lipid degradation, (4) documented improvement of HDL/LDL profile (Narkar 2008 and GSK phase 1). Advantages: no HPG axis suppression (non-androgenic mechanism), dramatically improved endurance empirically (+10-25% on sustained effort time), measurable increased lipid oxidation under effort, no need for post-cycle PCT. BUT major documented oncologic risk (Mitchell 2019, Endocrine Society): GlaxoSmithKline halted cardarine clinical development in 2007 after identification of multiple cancers (liver, bladder, testicle, skin, stomach) in rodents under pharmacological cardarine doses over 2 years. No long human RCT on oncologic safety. WADA status strictly banned in and out of competition since 2009. Typical dose in practice 10-20 mg/d × 6-8 weeks maximum, very short and spaced cycles. The risk-benefit is extremely unfavorable for non-competitive recreational use.
Combinaison ?
The ostarine + cardarine combo is a widespread practice in SARM-stacking for recomp (simultaneous muscle gain + fat loss). Typical scheme: ostarine 20 mg/d + cardarine 15 mg/d × 8 weeks, post-cycle PCT with nolvadex 20 mg/d × 4 weeks (for ostarine suppression; cardarine does not suppress the HPG axis). Both compounds act through complementary mechanisms: ostarine = protein synthesis and muscle preservation, cardarine = lipid oxidation and endurance. Practical effect: more pronounced body recomposition than with ostarine alone, possible in moderate caloric deficit. Biological monitoring: lipids (cardarine appears to improve HDL and LDL paradoxically), ALT/AST (ostarine can elevate transaminases), T total and LH (for ostarine). Preventive oncologic panel difficult to advise due to lack of practical tests but to keep in mind the Mitchell 2019 signal. Short cycles, long breaks (≥ 12 weeks between cycles). Sample recomp 8-week timeline: W0 baseline panel + body composition assessment (DEXA or InBody if available), W2 first energy/endurance subjective check, W4 mid-cycle full panel including lipids and ALT/AST, W6 cardio performance test (e.g., 5K time trial), W8 last dose, W8 PCT start for ostarine, W12 PCT end, W16 post-PCT and body composition recheck. Cardio integration: cardarine effects are dose-dependent and most pronounced when paired with structured endurance work (zone 2 for 30-45 min, 3-4× per week). Practical timing: take ostarine in the morning fasted with breakfast, cardarine pre-workout 30-45 min to align peak effect with training. Independent lab testing before cycle: vital for cardarine due to underground market mislabeling.
FAQ
- Is cardarine really carcinogenic?
- Concerning preclinical signal not replicated in humans (due to lack of long studies). Mitchell 2019 and the confidential GSK dossier (published partially after program halt) document cancers of multiple organs in rodents under pharmacological cardarine doses over 2 years. Suspected mechanism: chronic activation of PPARδ favoring cell proliferation in susceptible tissues. No long human RCT has been conducted to confirm or invalidate. The precautionary principle suggests avoiding, or limiting to very short cycles (< 8 weeks) and spaced (≥ 12 weeks between).
- Can ostarine be used by women?
- Yes, at moderate dose (5-10 mg/d × 6-8 weeks). Its low androgenicity and SARM mechanism (muscular selectivity) make it one of the best tolerated anabolic compounds for women. Low but not zero virilization risk: monitor acne, hirsutism, deep voice, clitoral hypertrophy. Immediate stop at first sign. Mild PCT (nolvadex 20 mg/d × 3 weeks) suffices. Complete hormonal panel before and after cycle.
- How much gains with ostarine + cardarine?
- Over 8 weeks at ostarine 20 mg/d + cardarine 15 mg/d in intermediate user in mild caloric deficit (-200 kcal/d): +2 to +4 kg lean mass and -2 to -4 kg fat, or net body recomposition of 4-8 kg of change. Excellent for users not wanting to do a classic AAS cycle. Cardio performance markedly improved (+10-20% on MAS time). Modest strength up +5-8%.
- Is cardarine banned in competition?
- Yes, since 2009. WADA classifies cardarine in the 'metabolic modulators' category (banned all periods, in and out of competition). Sensitive LC-MS/MS detection, 2-4 week detection window after last intake. Notorious positivity cases in cyclists (2008 Olympic Games, Tour de France). For any WADA-tested athlete, cardarine is to be absolutely avoided even out of competitive season.
- Do you need PCT after cardarine alone?
- No. Cardarine does not act on the androgen axis (PPARδ mechanism), so it suppresses neither testo nor LH/FSH. On cessation, return to baseline parameters is immediate. No SERM, no hCG needed. However, if paired with a SARM (ostarine, LGD-4033), the PCT for the latter remains essential.
- What biological monitoring for cardarine?
- ALT, AST, GGT, complete lipids, fasting glycemia at W0, W4, W8 of the cycle. Subjective monitoring of potentially oncologic symptoms (unusual digestive or urinary bleeding, palpable masses, unexplained weight loss). No practical tumor markers in routine, but quickly consult any suspect symptom. Complete panel 4-6 weeks post-cycle to confirm normalization.
- Does cardarine really improve lipid profile?
- Yes, paradoxically for a controversial compound. Narkar 2008 and early GSK phase 1 studies documented significant HDL improvement (+15-30%) and LDL and triglycerides decrease in cardarine subjects. Mechanism: PPARδ activation that favors hepatic lipid oxidation and reverse cholesterol transport. It was the main argument of clinical development before halt for oncologic signal. In bodybuilding practice, this 'cardio-protective' effect is invoked to counterbalance lipid degradation under AAS cycle — argumentation to weigh against theoretical oncologic risk.
- Is ostarine suitable for TRT?
- Not in first intention. TRT aims to restore a physiological testosterone level via exogenous testosterone (Bhasin 2018). Ostarine, being a SARM, does not cover complete androgenic activity and even suppresses the residual HPG axis — counterproductive in TRT. Some experimental protocols use weakly suppressive SARMs as TRT alternative, but no clinical consensus. For confirmed hypogonadism, testosterone remains the standard.