Low energy, stubborn belly fat, no drive in the gym, poor recovery. These point toward hormones, but hormones don't work in isolation. They sit downstream of your gut, liver, inflammation and nutrient status.
Start TRT without fixing that foundation and you can amplify the same problems. This guide covers what labs to run, what your GI-MAP shows, and what to address before or alongside any hormone therapy.
How to use this guide
Run your labs first. Then review your GI-MAP. Then build your protocol from the support sections with your provider. The goal isn't to avoid TRT. It's to make sure your body is ready to respond to it.
02 / 06
The Lab Panel
Ranges vary by lab, so always compare against your own report. "Optimal" ranges reflect common functional-medicine targets, not lab standards.
Hormone Markers
Marker
Standard Range
Optimal Range
Why It Matters
Total Testosterone
~264–916 ng/dL
700–1,100 ng/dL
Energy, muscle, drive. Low T is confirmed with two early-morning tests on different days, not one.
Free Testosterone
Varies by test method
Upper half of lab range
The usable portion. Often more telling than total.
Estradiol (sensitive)
~8–43 pg/mL
10–30 pg/mL
Too high or too low both hurt libido, mood and body composition.
SHBG
~10–56 nmol/L
20–40 nmol/L
Binds testosterone. High SHBG = less free T.
LH & FSH
Varies by lab
LH: 3–8 IU/L; FSH: 2–8 IU/L
Shows whether the issue starts in the testes or the brain.
Prolactin
~2–18 ng/mL
5–15 ng/mL
High prolactin suppresses testosterone.
DHEA-S
Depends on age
400–600 µg/dL
Adrenal hormone. Often low with long-term stress.
Metabolic & Thyroid Markers
Marker
Standard Range
Optimal Range
Why It Matters
Fasting Insulin
~2.6–24.9 uIU/mL
2–6 µIU/mL
Insulin resistance drives fat gain and more testosterone-to-estrogen conversion.
Fasting Glucose
~70–99 mg/dL
75–85 mg/dL
Poor blood sugar control is linked to lower T.
HbA1c
Under 5.7%
4.8–5.3%
3-month blood sugar average.
TSH
~0.45–4.5 mIU/L
1.0–2.0 mIU/L
Low thyroid mimics low-T symptoms.
Free T3
~2.0–4.4 pg/mL
3.4–4.2 pg/mL
Active thyroid hormone. Energy and metabolism.
Free T4
~0.8–1.8 ng/dL
1.3–1.7 ng/dL
Storage form. Conversion problems are common.
Reverse T3
~9–24 ng/dL
Under 12 ng/dL
Rises with stress, long diets and inflammation.
Inflammation & Liver Markers
Marker
Standard Range
Optimal Range
Why It Matters
hs-CRP
Under 3.0 mg/L
Under 1.0 mg/L
Whole-body inflammation.
Homocysteine
Under ~15 umol/L
6–8 µmol/L
Methylation marker. High = B vitamin and inflammation flag.
AST / ALT
~10–40 / ~7–56 U/L (varies)
15–25 U/L
Liver enzymes. Also rise after hard training, so retest after 3–5 days off.
GGT
~0–60 U/L (varies)
10–25 U/L
Liver-specific stress marker. Not raised by training.
ALP
~44–147 U/L
60–100 U/L
Bile duct and liver health.
Ferritin
~30–400 ng/mL
100–150 ng/mL
Iron stores. Also rises with inflammation.
Nutrient Markers
Marker
Standard Range
Optimal Range
Why It Matters
Vitamin D (25-OH)
30–100 ng/mL
40–50 ng/mL
Low vitamin D is linked to lower testosterone.
Magnesium (RBC)
~3.7–7.0 mg/dL (varies)
5.5–6.5 mg/dL
Sleep, stress and hundreds of enzyme reactions.
Zinc (plasma)
~60–130 mcg/dL
80–110 mcg/dL
Zinc deficiency lowers testosterone.
Vitamin B12
~200–1,250 pg/mL
600–1,000 pg/mL
Methylation, energy, nerves.
Folate (RBC)
Over ~280–500 ng/mL (varies)
Over 500 ng/mL
Methylation support.
Iron panel / TIBC
Varies
Serum iron: 85–130 µg/dL; TIBC: 250–350 µg/dL
Low iron causes fatigue that looks like low T.
TRT Safety Baseline
Get these before starting so your provider can track them once you're on TRT.
Marker
Why It Matters
CBC / Hematocrit
TRT raises red blood cells. A baseline lets you catch thick blood early.
PSA (men 40+)
Required before TRT by urology guidelines.
03 / 06
The GI-MAP
The GI-MAP is a DNA-based stool test that shows your gut bacteria, gut lining health and how well your gut is clearing hormones. Run it before any TRT decision.
The Estrobolome
The estrobolome is the group of gut bacteria that handle estrogen. When it's off, estrogen your liver tried to get rid of can come right back:
Liver packages estrogen
Sends it to the gut
High beta-glucuronidase unpacks it
Estrogen is reabsorbed
Estrogen load builds
Markers That Affect Hormones
Marker
What It Means for Hormones
Beta-glucuronidase
A key hormone marker. High levels unpack estrogen in the gut so it's reabsorbed. Driven by dysbiosis, low fiber, low plant variety and constipation.
Secretory IgA
Your gut's front-line immune defense. Low levels often show up with chronic stress.
Calprotectin
Gut inflammation. Hurts absorption of zinc, magnesium and B vitamins.
Elastase
Pancreatic enzyme output. Low = poor protein and fat digestion.
Steatocrit
Fat in stool. High = poor fat absorption, including vitamins A, D, E and K.
Zonulin (add-on)
A leaky gut marker. Useful, but stool zonulin results should be read with caution.
Bacteria to watch
H. pylori: can lower stomach acid and impair B12 absorption
Klebsiella and Citrobacter: can add to beta-glucuronidase and inflammation
Bacteroides fragilis: linked to gut lining damage
Candida / yeast: a dysbiosis driver
04 / 06
The Foundation Protocol
Build this with your provider based on your labs and GI-MAP. You don't need everything here. Start with what your results point to.
Gut Lining
Supplement
Dose
Why
L-Glutamine
5–10 g daily
Main fuel for gut lining cells. Empty stomach; build up slowly.
Zinc Carnosine
75 mg daily
Protects and repairs the gut lining. Contains about 16 mg zinc, which counts toward your daily zinc.
Colostrum (bovine)
500 mg–2 g daily
Growth factors that support gut repair.
DGL Licorice
400–800 mg before meals
Coats and protects the lining. Use DGL, not whole licorice.
Slippery Elm / Marshmallow
400 mg–1 g, up to 3x daily
Soothing coating for the gut lining.
Aloe (inner leaf)
50–200 mg daily
Calms the lining. Use decolorized, anthraquinone-free.
Butyrate
300–600 mg daily
Fuel for colon cells. Tightens the gut barrier.
Estrogen Clearance
Supplement
Dose
Why
DIM
200–400 mg daily with food
Shifts estrogen toward safer pathways. Can drop estradiol too low, especially on TRT, so recheck E2.
Calcium D-Glucarate
500–1,500 mg daily, split
Blocks beta-glucuronidase so packaged estrogen leaves the body. Best fit for high beta-glucuronidase.
Inflammation
Supplement
Dose
Why
Omega-3 (EPA/DHA)
2–4 g daily with meals
Lowers inflammatory signaling.
Curcumin
500–1,000 mg daily
Broad anti-inflammatory. Use an absorbable form (Meriva, BCM-95).
Boswellia (AKBA)
100–400 mg daily
Calms inflammatory pathways. Look for 30%+ AKBA.
Quercetin
500–1,000 mg daily
Calms mast cells and histamine.
Resveratrol
250–500 mg daily
Antioxidant. Aromatase effects are mostly shown in lab studies.
NAC
600–1,200 mg daily
Builds glutathione. Lowers oxidative stress.
Magnesium Glycinate
300–400 mg nightly
Supports sleep, stress and inflammation.
Vitamin D3 + K2
Dose to your labs
Upper limit is 4,000 IU/day without testing. Higher only with retesting. Pair with K2 (MK-7).
Zinc
15–30 mg daily
Needed to make testosterone. Keep total zinc (including zinc carnosine) at or under 40 mg/day; add 1–2 mg copper.
Liver & Bile Flow
Your liver processes estrogen, and bile carries it out through the gut. Slow bile flow means estrogen backs up.
Supplement
Dose
Why
Milk Thistle
400–600 mg daily
Protects liver cells.
TUDCA
250–500 mg daily
Protects the liver and improves bile flow.
Phosphatidylcholine
1–3 g daily
Main component of bile. Keeps bile thin.
Choline (CDP or Alpha-GPC)
300–600 mg daily
Needed for bile. Low choline is linked to fatty liver.
Taurine
1–3 g daily
Helps bile acids work.
Artichoke / Dandelion
300 mg–1 g daily
Gentle bile stimulants.
Betaine
500 mg–1 g daily
Supports methylation and liver fat metabolism.
Glutathione (liposomal)
250–500 mg daily
Main detox antioxidant.
Alpha Lipoic Acid
300–600 mg daily
Recycles glutathione.
Methylated B Complex
1 cap daily
Cofactors for liver detox and methylation.
Digestive support
With meals, as needed
Low elastase: pancreatic enzymes. High steatocrit or poor fat digestion: ox bile.
Stress & Cortisol
Chronic stress and high cortisol are linked to lower testosterone, worse sleep and more inflammation.
Supplement
Dose
Why
Ashwagandha (KSM-66)
300–600 mg daily
Lowers cortisol. Small trials show a testosterone boost. Rare liver injury reports, so stop if you see yellow skin or dark urine.
Rhodiola
200–400 mg daily
Improves stress response.
Phosphatidylserine
400–800 mg daily
Blunts the cortisol spike from training.
Vitamin C
1–2 g daily
Supports the adrenals and post-training cortisol.
Licorice Root
250–500 mg, short term
Only if cortisol is tested low. Raises blood pressure.
A note on peptides
BPC-157 and KPV are popular for gut repair, but neither is FDA-approved and most evidence is from animal studies. An FDA advisory panel voted in July 2026 to recommend allowing BPC-157 in compounding. The FDA hasn't made a final decision. BPC-157 is banned by WADA, which matters if you compete in tested sports. Only use peptides through a licensed provider.
05 / 06
Lifestyle Foundations
Sleep
Most of your daily testosterone is released during sleep. In one study, young men limited to 5 hours a night for a week saw testosterone drop 10–15%, about the same as aging 10–15 years.
Get tested for sleep apnea if you snore or wake up tired. It's a common hidden cause of low T.
Diet
Eat a wide range of colorful vegetables and fiber. Fiber helps carry estrogen out
Cut back on fried and ultra-processed foods
Prioritize wild-caught fish
Manage blood sugar
Limit alcohol. It raises estrogen and burdens the liver
Bone broth, collagen and fermented foods support the gut lining
Xenoestrogens
These are chemicals that act like estrogen in the body. Cut your exposure where you can:
Use glass or stainless steel instead of plastic
Filter your drinking water
Avoid canned foods and non-stick pans
Swap fragranced products for fragrance-free and paraben-free ones
Body Fat
Fat tissue converts testosterone into estrogen. Losing body fat is one of the most effective ways to improve your ratio.
06 / 06
TRT Readiness Checklist
The more you can check off, the better your results on TRT are likely to be.
A discussion checklist for your provider, not a medical clearance or readiness score.
Fertility comes first
TRT shuts down sperm production. If you want kids now or in the future, talk to your provider before starting. Fertility-preserving options exist.
The Bottom Line
TRT can be life-changing, but it's a tool, not a foundation. The men who get the best results do the work first: clear estrogen, heal the gut, lower inflammation and support the liver. Run the labs. Read the GI-MAP. Build the protocol. Then make your decision.
This guide is for educational purposes only and is not medical advice. Don't start, stop or change any medication or supplement without talking to your physician.