Pharmacokinetic Dose Calculator

• Substance Information

  • Substance Name: Enter the name of the substance.

  • Administration Type: Choose how the substance is administered, such as injection, oral, transdermal or sublingual.

  • Medication Concentration: Enter the concentration of the substance. The unit adapts automatically to the selected administration type.

• Pharmacokinetic Properties

  • Half-life: Enter the half-life and select the correct unit in days or hours.

  • Bioavailability (%): A suggested value appears automatically based on the administration type. You can adjust it if needed.

• Dosing Information

  • Target Weekly Systemic Dose: Enter the weekly amount you want to reach in milligrams.

  • Preferred Administration Interval: Choose how often you want to take or inject the substance and select the interval in days or hours.

  • Amount You Need to Administer: This is the amount you need to take each time to reach your target based on your goals and the substance concentration. It is calculated automatically and filled in for you. You can change it manually if you want and the "Target Weekly Systemic Dose" updates instantly.

  • Duration: Set the total duration of the protocol in weeks or days. You can also choose lifelong if it is meant for continuous therapy.

• Calculate: Click the calculate button to generate a complete dosage protocol.

• Results: You receive a full dosage protocol with all calculations and the average blood concentration, including a pharmacokinetic curve with a cumulative average.

• Download Button: With one click you can save the result as an image on your device. The image format is optimized and recommended because the tool's result view can appear less ideal on narrow screens depending on the device.

• Check: Always verify the results yourself and do not change any medication without consulting a healthcare professional.

Notice for Using the Tool

Before you decide to use steroids for performance reasons, you should take the time to understand their effects and possible side effects. It is always a good idea to consult reliable medical sources or speak with a qualified healthcare professional before making any decision. Keep in mind that oral compounds often carry stronger side effects, gels or similar forms are usually a waste of money, and the safest administration is generally intramuscular injection.

If you need additional features in the tool, I can easily expand it. Feel free to reach out with any ideas or suggestions.

But always discuss any use with a healthcare professional first, and never blindly rely on the results of this tool. Everyone is responsible for their own decisions and any potential consequences.

Practical Example

You want to use an injectable substance. You plan to administer about 150 mg per week of the chosen substance through intramuscular injections. The concentration of the medication is 250 mg per milliliter. The half life of this compound is about 5 days, which means it stays active in the blood for several days. You choose an injection interval of every 7 days.

The tool calculates that the required injection volume is 0.6 ml per application. If you follow this plan for 10 weeks, the final average blood concentration will be 144 mg. In addition to the average level of the substance in your blood, you can also see the peak values after each injection, which are a bit higher in this example because the dosing interval is longer than the half life.

Correct Injection Angles

As mentioned before, all of this information should always be discussed thoroughly with a medical professional. The following overview is only a small reminder and shows the most important types of injections, their typical angles, and suitable needles.

• Intramuscular Injections
  With this method, the medication is injected deep into a skeletal muscle. Typical injection sites include the deltoid muscle in the upper arm, the gluteal muscles, or the thigh muscle. Intramuscular injection allows for rapid absorption of the active substance into the bloodstream and is often used for vaccines, depot preparations, and medications with larger volumes. The needle is inserted at a 90° angle.
  
  For intramuscular injections, needles typically have a length between 22 and 25 mm and a thickness of approximately 25 to 27 Gauge (= outer diameter Ø 0.5 mm to Ø 0.4 mm). Common injection sites are the deltoid muscle in the upper arm, the lateral thigh muscle (Vastus lateralis), and the hip (ventrogluteal area). During the IM injection procedure, the skin is often stretched or pulled using the Z-Track technique to keep the medication in the muscle and protect soft tissue.
  
  

• Subcutaneous Injections
  These injections are administered into the fatty tissue beneath the skin (subcutis). They are suitable for medications that need to be absorbed slowly and evenly, such as insulin, blood thinners, or allergy medications used in desensitization therapy. The needle is usually inserted at a 45° angle.
  
  For subcutaneous injections, needles are shorter than for IM injections, typically about 12 to 16 mm, to avoid inserting the needle too deeply and to allow slower absorption. The needle thickness is usually between 25 and 30 Gauge (= outer diameter Ø 0.5 mm to Ø 0.3 mm). Many medications for subcutaneous injection (such as insulin) are also available in prefilled pens, which simplify administration.
  
  

• Intravenous Injections
  Here, the medication is injected directly into a vein. This method allows for very rapid action, as the substance enters the bloodstream immediately. It is often used in hospitals during emergencies, or for administering fluids, medications, or nutrients. The needle is inserted at a shallow angle of about 25° to the skin surface.
  
  For intravenous injections, specialized cannulas or thinner needles are commonly used to establish venous access safely and as painlessly as possible. The choice of needle gauge and length depends on the vein size and the type of infusion, typically ranging from 20 to 24 Gauge (= outer diameter Ø 0.9 mm to Ø 0.6 mm).
  
  

• Intradermal Injections
  Intradermal injections are given into the middle layer of the skin (the dermis), just beneath the epidermis. This technique is mainly used for allergy tests or tuberculosis screenings. The needle is inserted very shallowly at an angle of 10–15°, and a small bleb (wheal) forms at the injection site.
  
  Intradermal injections require very short needles, often around 8 mm in length, since only the uppermost skin layer needs to be reached. The typical needle thickness is 25 to 27 Gauge (= outer diameter Ø 0.5 mm to Ø 0.4 mm), allowing precise administration without penetrating too deeply.