Summary: Blood work provides objective data on how your body responds to peptides. Understanding normal ranges, key markers, and how to interpret patterns helps you monitor safety. Key markers to track include hormones (testosterone, GH, thyroid), liver enzymes, kidney function, blood counts, and metabolic markers. Changes over time matter more than single results. Consult healthcare providers to interpret concerning findings and guide protocol adjustments.
Understanding Test Result Formats
Lab results show: test name, your result, normal range (reference interval), and sometimes a flag (high/low indicator).
Normal ranges vary among labs due to different equipment and methods. A result “high” at one lab might be “normal” at another. Compare your results against your lab’s reference ranges, not general ranges.
Reference ranges represent the middle 95% of healthy population. A value outside the range isn’t automatically concerning—some healthy people fall outside ranges. But out-of-range values warrant investigation.
Some tests have different normal ranges for males versus females. Testosterone normal range differs for men and women. Hormone results always specify which range applies.
Key Hormone Markers
Testosterone
Testosterone is a primary hormone affecting muscle growth, metabolism, mood, and sexual function. Normal ranges: men typically 300-1000 ng/dL, women typically 15-70 ng/dL (varies by lab).
High testosterone might indicate excessive peptide stimulation, anabolic steroid use, or in some cases, a health problem. Excessively high levels increase cardiovascular risk and other complications.
Low testosterone causes fatigue, mood changes, decreased muscle, and sexual function issues. Testosterone naturally decreases with age. Peptide protocols should maintain healthy testosterone levels.
Interpret testosterone alongside free testosterone (the fraction circulating freely) and SHBG (sex hormone binding globulin, which binds testosterone). High SHBG reduces free testosterone even if total testosterone is normal.
Growth Hormone (GH)
Growth hormone regulates growth, metabolism, and body composition. GH is released in pulses throughout day, making single measurements less meaningful than growth hormone response tests.
IGF-1 (insulin-like growth factor 1) is more stable and easier to measure. IGF-1 rises when growth hormone is adequate. Normal IGF-1 depends on age—younger people have higher normal ranges.
Very high GH or IGF-1 can cause acromegaly (excessive growth), diabetes, and cardiovascular problems. Very low levels cause poor recovery and muscle loss.
Thyroid Function
TSH (thyroid stimulating hormone) controls thyroid. Normal TSH typically 0.5-5.0 mIU/L. High TSH suggests hypothyroidism (underactive thyroid). Low TSH suggests hyperthyroidism (overactive thyroid).
Free T4 and Free T3 show how much thyroid hormone is active. Many peptides affect thyroid function—monitoring prevents problems.
Thyroid antibodies (TPO antibodies, thyroglobulin antibodies) indicate autoimmune thyroid disease. Autoimmune thyroid issues require special monitoring with certain peptides.
Estrogen and Progesterone
In women, estrogen and progesterone fluctuate throughout menstrual cycle. Labs should be drawn at consistent cycle timing for meaningful interpretation. Some peptides affect estrogen/progesterone balance—monitoring is important.
In men, estrogen should be low but not absent. Very high estrogen in men causes gynecomastia (breast tissue growth) and other issues. Very low estrogen causes joint problems and mood issues.
Liver Function Tests
Liver function tests assess liver health. Many peptides are metabolized through the liver, so monitoring is important.
AST and ALT
AST and ALT are liver enzymes. Normal: typically under 40 U/L. Elevated levels suggest liver stress or inflammation. Very high levels suggest liver damage.
AST/ALT ratio helps identify cause. Ratio less than 1 suggests non-alcoholic fatty liver disease (NAFLD). Ratio greater than 2 suggests alcoholic liver disease. Isolated elevation suggests muscle or heart damage.
Bilirubin
Bilirubin is a waste product broken down by liver. Normal: typically under 1.2 mg/dL. Elevated bilirubin suggests liver isn’t processing waste properly. Very high bilirubin causes yellowing of eyes and skin.
Bilirubin is divided into unconjugated (indirect) and conjugated (direct) forms. High conjugated bilirubin indicates liver dysfunction. High unconjugated bilirubin might indicate hemolysis (excessive red blood cell breakdown) or other issues.
Alkaline Phosphatase (ALP) and GGT
ALP and GGT are enzymes indicating bile flow. Elevated levels suggest cholestasis (bile flow obstruction) or liver infiltration.
If ALP is elevated but GGT is normal, elevated ALP might be from bone. If both are elevated, liver is the source.
Albumin and Globulins
Albumin is a protein made by liver. Low albumin suggests liver dysfunction or nutritional deficiency. Albumin also indicates nutritional status.
Globulins are immune proteins. Abnormal globulin ratios suggest immune issues.
Kidney Function Tests
Kidneys eliminate peptide metabolites. Monitoring kidney function ensures peptides aren’t causing damage.
Creatinine
Creatinine is a waste product cleared by kidneys. Normal: typically 0.6-1.2 mg/dL. Elevated creatinine suggests kidney dysfunction.
Creatinine varies with muscle mass—muscular people have higher creatinine. Use GFR (glomerular filtration rate) for more accurate assessment.
BUN (Blood Urea Nitrogen)
BUN is another kidney filtration marker. Normal: typically 7-20 mg/dL. Elevated BUN suggests kidney dysfunction, dehydration, or high protein intake.
BUN/creatinine ratio can indicate problem type. High ratio suggests dehydration or liver disease. Low ratio suggests kidney disease or malnutrition.
eGFR (Estimated Glomerular Filtration Rate)
eGFR estimates how much kidney function you have. Normal: eGFR greater than 60. Values below 60 suggest kidney disease. eGFR below 15 indicates kidney failure.
eGFR accounts for age, sex, and race in addition to creatinine—it’s more accurate than creatinine alone.
Blood Count Markers
Hemoglobin and Hematocrit
Hemoglobin (normal: men 13.5-17.5 g/dL, women 12-15.5 g/dL) carries oxygen. Low hemoglobin causes fatigue and poor performance. High hemoglobin increases cardiovascular risk.
Hematocrit (normal: men 41-53%, women 36-46%) is percentage of blood that’s red cells. It rises with peptides affecting growth hormone or other factors.
Some growth hormone peptides cause elevated hemoglobin/hematocrit—this increases cardiovascular risk and might require intervention.
White Blood Cells (WBC)
WBC normal range: 4.5-11.0 cells/1000 μL. Low WBC suggests immune suppression. High WBC suggests infection or immune activation.
Peptides affecting immune function should be monitored via WBC.
Lipid Panel and Metabolic Markers
Total Cholesterol, LDL, HDL, Triglycerides
Total cholesterol normal: under 200 mg/dL. Higher levels increase cardiovascular disease risk.
LDL (“bad” cholesterol) normal: under 100 mg/dL. Higher levels increase cardiovascular risk.
HDL (“good” cholesterol) normal: men over 40 mg/dL, women over 50 mg/dL. Higher is better.
Triglycerides normal: under 150 mg/dL. Elevated triglycerides increase cardiovascular risk.
Some peptides worsen lipid profiles—monitoring prevents cardiovascular complications.
Glucose
Fasting glucose normal: 70-100 mg/dL. Elevated glucose suggests diabetes risk or actual diabetes.
Fasting insulin normal: 2-12 mIU/L. Elevated insulin suggests insulin resistance.
Peptides affecting growth hormone or metabolism affect glucose regulation—monitoring prevents metabolic complications.
Interpreting Patterns Over Time
Single results are less meaningful than patterns. Compare current results to baseline and previous results.
Results improving toward normal over time suggest your body is adapting well. Results worsening suggest protocol adjustment is needed.
Spike in one marker followed by return to baseline might represent normal variation. Consistent elevation suggests problem requiring intervention.
When to Consult Healthcare Providers
Understand your results, but don’t self-diagnose. Concerning results should be discussed with healthcare providers who can:
- Interpret results considering your complete health picture
- Identify whether elevations represent problems or expected variation
- Recommend adjustments or interventions
- Rule out alternative causes
Seek immediate provider input for: markedly abnormal results, results changing significantly from baseline, or if you have symptoms paired with abnormal results.
