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Testosterone

• A hormone naturally produced in male and female bodies.
• It can be “aromatized” by the aromatase enzyme and turned into estrogen, primarily thought of as a type of estrogen called “estradiol” (also known as E2).
• It can be “5-alpha-reduced” (5ar) by the 5-alpha reductase enzyme and turned into dihydrotestosterone.
• Enzymes are catalysts of reactions that occur in your body. If there are fewer active catalysts, then fewer of their relevant reactions will occur.
  • Example: An aromatase inhibitor can make some aromatase enzymes inactive. This results in less estrogen because there are fewer opportunities for the reaction (aromatization) to occur.

Estrogen

• A hormone naturally produced in male and female bodies.
• Two relevant forms: estrone (E1), a weaker estrogen; and estradiol (E2), a stronger estrogen. When people talk about “estrogen,” they’re mainly referring to estradiol.
• Critical for brain health, sexual wellness, mood, cognition, complexion, and health.
• Every person has a different tolerance to elevated estrogen levels.
  • Example: Introducing an aromatase inhibitor in a man with high estrogen but no intolerable effects would be an unreasonable approach.

SHBG (Sex Hormone-Binding Globulin)

• Binds to testosterone, making it bound testosterone.
• When bound, testosterone is shuttled by SHBG to regions of the body that need the testosterone and is prevented from binding to anything else along the way.
• Free testosterone is testosterone not bound by SHBG, allowing it to interact with any androgen receptor sites as soon as it encounters them.
• Total testosterone is a bloodwork marker that measures the combined amount of testosterone bound by SHBG and testosterone not bound by SHBG (free testosterone).
  • Total testosterone is not always indicative of how well you will accrue muscle/strength, and the same is true about free testosterone—but they are both correlated with it.

TRT (Testosterone Replacement Therapy)

• The practice of using exogenous (out-of-body) testosterone to replace insufficient or unoptimized natural testosterone production.
• TRT dosing protocols can range from 1mg per kg to 3mg per kg or more per week, depending on the genetic makeup of the individual.
• TRT may be prescribed as pellets inserted under the skin, topical gels, or injectable testosterone—with injectable testosterone being the most effective administration by far.
  • Most men can handle testosterone at 300mg/wk for the rest of their life with minimal complications, assuming health is responsibly managed.
  • Testosterone levels do not universally react to exogenous testosterone in the same way.
    • Example: A man who uses 300mg/wk may have total testosterone levels of 1200ng/dl, whereas another man who uses the same dose may have 2700ng/dl.

Testosterone Dosing

• Can be determined via the milligram per kilogram approach or arbitrarily.
  • No dosing practice is necessarily more correct than the other.
  • The best dose is the one that your body responds to the best—everyone has their own sweet spot which changes as their physique and goals change.
• The milligram per kilogram approach is a dosing practice that adjusts weekly dose recommendations depending on the body weight of the user in kilograms.
  • This is a very common practice in modern medicine—the theory is that anabolic applications can successfully mimic this.
  • For beginners, the mg/kg approach is often more successful at landing in the user’s sweet spot than the arbitrary approach.
  • Very generalized ranges for reference:
    • 1mg/kg is western medicine TRT.
    • 2mg/kg is modern TRT.
    • 3mg/kg is optimized TRT or beginner cycle.
    • 4mg/kg is sports TRT or beginner cycle.
    • 5mg/kg is a mild cycle, etc.
  • Example: 4mg/kg for a 90kg male would yield a testosterone dose of 360mg/wk.

Testosterone Action

• Exerts anabolic and androgenic action all over the human body, to greater or lesser degrees depending on the genetic sensitivity to testosterone of the individual.
  • Anabolism refers to building muscle, androgenicity refers to masculinizing effects.
  • You may have seen an anabolic:androgenic ratio for each steroid, but this metric is largely useless because of how it is determined.
  • Androgenicity includes even undesirable “masculinizing” effects, such as male pattern baldness (hence the official name, “androgenic alopecia”), and excess body hair.
  • This explains the full name of steroids, “Anabolic Androgenic Steroids,” or AAS for short.

Esters

• Modifications to compounds to alter how long it takes the body to process them.
  • Testosterone without an ester (test no ester, TNE) is a rapid compound that is in and out of your system in a very short amount of time, which isn’t convenient for enhancement.
  • Testosterone enanthate has a half-life of 5-7 days, allowing users to inject much less frequently and avoid severe hormone fluctuations.
  • Sustanon is a blend of short and long esters of testosterone (propionate, phenyl-propionate, isocaproate, and decanoate), making for an interesting half-life curve.
  • Compounds besides testosterone are also esterified.
    • EQ is the extremely long undecylenate ester of boldenone, which can also be found as the shorter boldenone cypionate ester and the much shorter boldenone acetate ester.
    • NPP is the phenyl-propionate ester of nandrolone, and Deca is the decanoate ester of nandrolone—they are the same steroid, but with different half-lives.

Half-Life

• The time it takes the body to halve the amount of a compound in its system.
  • After administration, the amount of a compound in your system grades up from zero, reaches its peak serum concentration, and then begins to decline on its half-life curve.
  • Example: The cypionate ester of testosterone has a half-life of 7 days—if you injected 100mg, by next week you would have 50mg still in your system.
• Half-lives can be stacked on top of each other to achieve greater concentrations in the body.
• Example: Injecting 100mg testosterone cypionate once per week for demonstration purposes:

• • Week 1: 100mg₁
  • Week 2: (100*0.5¹=50)₁ + 100₁ = 150mg
  • Week 3: (100*0.5²=25)₁+ 50₂ + 100₃= 175mg
  • Week 4: (100*0.5³=12.5)₁ + 25₂ + 50₃ + 100₄ = 187.5mg
  • Week 5: (100*0.5⁴=6.25)₁ + 12.5₂ + 25₃ + 50₄ + 100₅ = 193.75mg
  • Week 6: (100*0.5⁵=3.125)₁ + 6.25₂+ 12.5₃ + 25₄ + 50₅ + 100₆ = 196.875mg

• Note: Injecting testosterone cypionate once per week is a very bad idea. The user will be at much greater risk of side effects than if they divided their weekly dose across every other day or everyday injections. The above numbers are ONLY for demonstration purposes.
• To track half-lives, the injection week is noted in subscript beside each serum number (Ex: 25\(_4\) means the injection from week 4, which has undergone two half-lives: 100 → 50 → 25).
• For easier visualization (and less math), consider tools such as Steroid Plotter.

The Steroid Family Tree

• All AAS are divided into three categories with general properties:
  • Dihydrotestosterone (DHT) derivatives
  • Testosterone derivatives
  • 19-nortestosterone / Nandrolone derivatives
• A derivative is an adjusted version of the original molecule.
  • Example: Primobolan being an adjusted version of Dihydrotestosterone.

DHT Derivatives

• Don’t aromatize into estrogen, & can’t be 5ar into DHT.
  • Some DHT derivatives have the potential for downward pressure on estrogen levels, such as Primobolan and Masteron. The degree of their downward pressure varies genetically.

Testosterone Derivatives

• Aromatize into some kind of estrogen, and can be 5ar.
  • Example: Boldenone aromatizes* into synthetic E1, Dianabol aromatizes into methyl-E2.
  • Exception: Halotestin, which does not aromatize

due to its unique molecular structure (see Steric Hindrance).

Nandrolone Derivatives

• Aromatize into very little estrogen, can be 5ar into a weak DH compound.
  • Nandrolone derivatives are very androgenic, whereas their 5ar counterparts are not.
  • Example: If a 5ar inhibitor is combined with nandrolone, more hair loss would occur than using nandrolone alone because it is prevented from 5ar into its less androgenic form.

AAS and Natural Testosterone Production

• When AAS are introduced into the human body, natural testosterone production is suppressed.
  • The degree of suppression depends on dose and duration of AAS use.
  • Suppression is a signal that is continually sent to your body during AAS use.
  • This signal informs your body to stop producing natural testosterone.
  • Suppression fades after stopping AAS use, and is considered gone after 5 half-lives.
  • Effective doses of AAS are almost guaranteed to fully suppress natural testosterone production.
  • Individuals cannot always recover fully from a suppressed state, depending on their genetics.
    • Example: Some case studies of very sensitive people administering a single dose of AAS and never recovering their testosterone levels within 90% of their original values.

Measurements and Concentrations

Basic scientific units are used regularly. Here are some important ones to know:

• Milligrams (mg), a measurement of a solid substance such as in a powder vial of MT-2
• Micrograms (mcg), a measurement of a solid substance. Conversion: 1mg = 1000mcg
• Milliliters (mL or ml), a measurement of volume usually of a liquid such as BAC water
• International Units (IU), a measurement of growth hormone and HCG (among others).
• IUs are a weird unit, think of them like mg or mcg but without any conversion; they differ for every individual compound
• Example, 10IU of GH is the same “size” as 5000IU of HCG

Liquids are measured in milliliters (mL) or cubic centimeters (cc) if using standard syringes, or units if using insulin syringes.

• 100 units on an insulin syringe = 1mL or 1cc on a standard syringe
• Your syringe is standard if it’s in single digits and decimal places
• Your syringe is an insulin syringe if it goes up to double digits to 50 (½cc) or to 100 (1cc)

Concentration is the amount of a compound in any given liquid (oil, water, solvent, etc).

• The most common measurements are mg/mL (milligrams per milliliter) and mcg/mL (micrograms per milliliter)
• To find the concentration, divide the amount of compound by the amount of liquid
• Example, you add 2mL of bacteriostatic water to 10mg of a compound. The concentration is 10mg / 2mL = 5mg per mL.
• Example (IU), you add 2mL of bacteriostatic water to 5000IU of a compound. The concentration is 5000IU / 2mL = 2500IU per mL.

The higher the concentration of an oil-based compound like testosterone, the more uncomfortable the injection.

• Testosterone 300mg/mL or below is generally well tolerated if brewed properly
• Example, Test 400, if it is legitimately 400mg/mL, makes for an unpleasant injecting experience in most users