HRT Transdermal Spray Tutorial

Transdermal estradiol bypasses liver metabolism and doesn’t require injections. This tutorial explains how to make an estradiol spray bottle which is a convenient way to apply transdermal estradiol and doesn’t require handling gelling agents.

Supplies

Tools (non-consumable):

Consumables:

  • 99% Isopropyl Alcohol - The main solvent for the API.
  • Isopropyl Myristate - Penetration enhancer to improve bioavailability.
  • Polysorbate 80 - Emulsifier to prevent separation of excipients.
    • From Amazon - Note: Amazon version is a cosmetics grade product, whereas SpecializedRx sells NF grade.
  • 30mL Spray Vials - Used to store and administer spray.

APIs:

We suggest buying APIs from TeaHRT or Allie.

Recipe

200mL of 20 mg/mL solution

Ingredient Percentage Volume (mL) Density (g/mL) Mass (g)
Estradiol 4
Isopropyl Alcohol 45% 90 0.786 70.74
Isopropyl Myristate 45% 90 0.85 76.5
Polysorbate 80 10% 20 1.102 22.04
Total 173.28

Transdermal Progesterone

You can also use this recipe to make transdermal progesterone.

200mL of 60 mg/mL solution

Ingredient Percentage Volume (mL) Density (g/mL) Mass (g)
Progesterone 12
Isopropyl Alcohol 45% 90 0.786 70.74
Isopropyl Myristate 45% 90 0.85 76.5
Polysorbate 80 10% 20 1.102 22.04
Total 181.28

Procedure

Wear gloves and ensure your workspace is clean. Ensure the beaker and other lab supplies are clean before starting, however with transdermal solutions sterility isn’t as big of a concern as other methods.

  1. Weigh out all of the ingredients into your beaker using the recipe above.
  2. Place your beaker onto the hot plate at low heat and stir until dissolved.
    1. Isopropyl Alcohol is very volatile. Avoid heating it excessively (ideally do not heat at all) and avoid open flames.
  3. Remove the mixture from heat and allow it to cool until you can comfortably touch the beaker with your hands.
  4. Fill your bottles with the solution and cap them.
    1. A funnel or pipette may help with this process.

Administration

The solution may separate, so it is important to shake well before use.

Typically people administer 1 full spray every 8-12 hours either on the scrotum or armpit for increased absorption. Each spray is equal to 0.1mL of solution and 2mg of estradiol. Note that the armpit area is near breast tissue which some people may want to avoid and has less absorption. Some people may need to administer two sprays.

Each 30mL bottle contains 600mg of estradiol. At the dosage listed above, a bottle should last 50-150 days. The entire batch should last 333-1000 days.