The SARM studies tracked a short list of blood markers, and those are the ones worth knowing: total and free testosterone, SHBG, LH and FSH (suppression), HDL cholesterol and the lipid panel, and liver enzymes (ALT, AST) and bilirubin. MK-677 studies add IGF-1 and blood sugar markers; the labels of PCT drugs add estradiol, hematocrit and PSA. This guide explains what each marker shows, which compounds’ studies tracked it, when to test so the result reflects your own body, and the typical adult male reference ranges.
It is not medical advice, and no range replaces your own lab’s. To time a test for a specific stack, use the PCT & Bloodwork Planner.
The core markers and why they matter
| Marker | What it shows | Changed in studies of | Typical adult male range |
|---|---|---|---|
| Total testosterone | Your testosterone, bound and free | Ostarine, LGD-4033 (down); SERMs, anastrozole (up) | 249–836 ng/dL (8.6–29.0 nmol/L) at ages 17–50 (MedlinePlus); 264–916 ng/dL in healthy non-obese men aged 19–39 on a harmonized scale (Travison 2017) |
| Free testosterone | The part not bound to proteins, available to tissues | LGD-4033 (down at 1 mg/day); unchanged on ostarine 1–3 mg/day | Lab-specific |
| SHBG | The protein that carries testosterone | Ostarine, LGD-4033, RAD-140 (down); tamoxifen, clomiphene (up) | Lab-specific |
| LH | The brain’s signal to the testes to make testosterone | SERMs (up); low or normal with low testosterone = suppression pattern | 1.8–8.6 IU/L (MedlinePlus) |
| FSH | The brain’s signal for sperm production | LGD-4033 (down at 1 mg/day); SERMs (up) | 1.5–12.4 mIU/mL (MedlinePlus) |
| Estradiol | Main estrogen; men need some for bone and body fat | Clomiphene (up), anastrozole (down) | 10–50 pg/mL (MedlinePlus) |
| HDL cholesterol | “Good” cholesterol | Ostarine (−17 to −27%), LGD-4033, clomiphene (down) | 40 mg/dL or more; under 40 is low, 60 or more is best (MedlinePlus) |
| LDL and total cholesterol | “Bad” cholesterol and the total | LGD-4033 + MK-677 case (LDL +40%) | LDL under 100 mg/dL; total under 200 mg/dL (MedlinePlus) |
| ALT | Liver cell damage | Ostarine (dose-dependent rise), RAD-140 (up in 45%) | 4–36 U/L (MedlinePlus) |
| AST | Liver (and muscle) cell damage | RAD-140 (up in 59%) | 8–33 U/L (MedlinePlus) |
| Bilirubin | Bile flow; rises in cholestatic liver injury | RAD-140 trial; SARM liver-injury case reports | Total 0.1–1.2 mg/dL (MedlinePlus) |
| Hematocrit | Share of blood made of red cells | Enclomiphene (safety concern per EMA) | 37–48% on one MedlinePlus page (MedlinePlus), 40–55% on another (MedlinePlus CBC): labs differ |
| PSA | Prostate marker | Enclomiphene (safety concern per EMA) | Up to 4.0 ng/mL; usually under 2.5 for men in their 50s or younger (MedlinePlus) |
| IGF-1 | Growth hormone activity | MK-677 (up); tamoxifen and enclomiphene (down) | Age-specific; use your lab’s range |
| Fasting glucose, HbA1c | Blood sugar | MK-677 | Fasting 70–99 mg/dL (MedlinePlus); HbA1c under 5.7% (5.7–6.4% is prediabetes) (MedlinePlus) |
| Prolactin | Pituitary hormone; high levels can lower libido | MK-677 trials tracked it | Under 20 ng/mL (MedlinePlus) |
The “changed in studies” column comes from our compound records: ostarine (Dalton 2011), LGD-4033 (Basaria 2013), RAD-140 (2022), the LGD-4033 + MK-677 case (Cardaci 2022), clomiphene (Soares 2018), tamoxifen (Birzniece 2010), enclomiphene (EMA 2018) and anastrozole (Leder 2004).
Bloodwork per compound
These are the markers each compound’s studies tracked, from our records. They show what research measured, not a monitoring plan.
| Compound | Markers the studies tracked | Why |
|---|---|---|
| Ostarine | Total and free testosterone, LH, FSH, SHBG, lipid panel, ALT/AST, bilirubin, calcium | Testosterone, SHBG, HDL, liver enzymes and calcium changed in enobosarm trials; bilirubin rose in liver-injury case reports |
| LGD-4033 | Total and free testosterone, LH, FSH, SHBG, lipid panel, ALT/AST, bilirubin, PSA, hematocrit | Measured in the 21-day trial; bilirubin rose in the liver-injury case reports |
| RAD-140 | ALT/AST, bilirubin, total and free testosterone, LH, FSH, SHBG, lipid panel | Liver enzymes, bilirubin and SHBG changed in the Phase 1 trial; the hormone markers changed in trials of other SARMs |
| MK-677 | IGF-1, fasting glucose, HbA1c, fasting insulin, ALT/AST, prolactin, lipid panel | Tracked in its clinical trials; blood pressure and swelling were also watched |
| Cardarine | Lipid panel, ALT/AST, fasting glucose and insulin, CK | Lipids, liver fat and insulin changed in human trials; CK and liver enzymes were very high in a case report |
| Enclomiphene | Total testosterone, LH, FSH, estradiol, hematocrit, PSA, semen analysis | Measured in the trials and named as safety concerns by EMA |
| Clomiphene | Total testosterone, LH, FSH, estradiol, SHBG, HDL, hematocrit, PSA, liver tests | Measured in the studies or named in the label |
| Tamoxifen | Liver tests, blood count with platelets, total testosterone, LH, FSH, SHBG, estradiol | The label advises periodic blood counts and liver tests (label) |
| Anastrozole | Estradiol, total testosterone, LH, lipid panel, bone density (DXA), liver tests | The label advises considering cholesterol and bone density monitoring (label) |
Source: Sarmguide compound database.
When people test
The studies give a template for timing:
- Before the first dose (baseline). The HAARLEM study of 100 steroid users tested before the cycle, at its end, 3 months after it, and one year after the start (Smit 2021). Without a baseline, an after-cycle result has nothing to be compared with.
- During the cycle, for markers that signal harm rather than suppression: liver enzymes and bilirubin (liver-injury case reports appeared after weeks to months of use) and lipids. The LGD-4033 trial measured blood counts, chemistry, lipids and hormones during dosing (Basaria 2013).
- After the compound has cleared, to see your own hormones. After five half-lives about 3% of a drug is left (StatPearls). With the half-lives in our records: ostarine about 3–5 days, LGD-4033 about 5–8 days, RAD-140 about 9 days, enclomiphene about 2 days, anastrozole about 10 days, tamoxifen about 4–5 weeks. These are blood clearance times, not drug-test detection windows.
- Later follow-up. In the LGD-4033 trial, hormones were back to baseline five weeks after the last dose (Basaria 2013). After steroids, testosterone took about 3 months and sperm about a year (Smit 2021).
How to take the test. For testosterone, the Endocrine Society recommends a fasting, morning sample, and repeating it to confirm a low result (Bhasin 2018). Testosterone is usually highest between 7 and 10 in the morning (MedlinePlus).
How to read the results
| Pattern | What it usually means | Relevant evidence |
|---|---|---|
| Low total testosterone, low or normal LH and FSH | The brain’s signal is switched down: the suppression pattern (secondary hypogonadism) | Definition used by FDA’s 2022 review (FDA 2022) |
| Low total testosterone, normal free testosterone, low SHBG | Mostly a fall in the carrier protein, not in available testosterone | Ostarine at 1–3 mg/day lowered total testosterone and SHBG while free testosterone held (Dalton 2011). The guideline advises free testosterone when SHBG is altered (Bhasin 2018) |
| Low HDL | A known SARM effect | HDL fell with dose on LGD-4033 and returned after stopping (Basaria 2013); −17 to −27% on ostarine (Dalton 2011) |
| High ALT, AST or bilirubin | A liver signal | Case reports of cholestatic liver injury with ligandrol (Barbara 2020), ostarine (Mertens 2024) and RAD-140 (2026); see are SARMs liver toxic |
| High estradiol on a SERM, or very low estradiol on anastrozole | Expected drug effects, each with costs | Estradiol rose on clomiphene (Helo 2015); very low estrogen raised body fat and lowered sexual function in men (Finkelstein 2013) |
| High hematocrit or PSA | Safety signals that guidelines take seriously | The Endocrine Society advises against starting testosterone therapy with an elevated hematocrit, or with PSA above 4 ng/mL (above 3 in higher-risk men) without urological evaluation (Bhasin 2018) |
| Low FSH that stays low after the cycle | Sperm production may be slow to recover | FSH was still below the reference range after the cycle in the LGD-4033 + MK-677 case (Cardaci 2022); a semen analysis measures sperm directly (concentration 15–259 million/mL is typical) (MedlinePlus) |
Ranges differ between labs. The harmonized testosterone study found that much of the difference between cohorts came from the assays themselves (Travison 2017). Compare a result with your own lab’s range, and with your own baseline from the same lab.
What bloodwork cannot tell you
- What was in the bottle. In 2017, only 52% of 44 products sold as SARMs contained a SARM (Van Wagoner 2017). A blood test shows effects, not identity.
- How you feel. Low testosterone in men can bring low sex drive, muscle loss and breast enlargement (MedlinePlus), but feelings and lab values do not always match.
- Blood pressure, which is measured with a cuff, not a blood test. See SARMs and blood pressure.
Related: SARMs PCT (suppression evidence for each compound), low testosterone blood test, SARMs database.