THC Bath Bomb Recipe
Combine 1 cup baking soda, 1/2 cup citric acid, 1/2 cup cornstarch, 1/2 cup Epsom salt, and 1/4 cup cannabis-infused coconut oil. Press the mix into molds. Dry 24 to 48 hours. THC is fat soluble and not water soluble. In a tub it stays with the oil and disperses into the water. Skin absorbs a small share. The result is fizz, scent, and softer water, not a high.
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Ingredients
- 1 cup baking soda
- 1/2 cup citric acid
- 1/2 cup cornstarch
- 1/2 cup Epsom salt
- 1/4 cup cannabis-infused coconut oil, chilled until solid
- 1 tbsp polysorbate 80 (optional, helps the oil disperse and cuts tub residue)
- 10 to 15 drops essential oil (optional)
- witch hazel in a spray bottle
Steps
- Whisk the baking soda, citric acid, cornstarch, and Epsom salt in a bowl. Break up lumps with your fingers.
- Add the coconut oil and polysorbate 80. Rub the mix between your palms until it holds shape when squeezed.
- Spray witch hazel 3 to 4 times over the mix. Whisk. Repeat until the texture looks like damp sand. Do not add water. Water starts the fizz.
- Pack the mix into silicone molds. Press hard so the bombs hold together.
- Let the molds sit 24 to 48 hours in a dry room. Flip after 12 hours.
- Pop the bombs out. Store in an airtight jar away from light and heat. Use within 3 months.
THC Dose Per Bath Bomb
Commercial cannabis bath bombs list 10 mg to 100 mg THC per unit. For a home batch, start with the oil. Decarb 7 g of flower that tests 20% THC. Infuse it into 1 cup of coconut oil. That cup holds about 1,400 mg THC. This recipe uses 1/4 cup, or about 350 mg. Divide the batter into 8 molds and each bomb holds about 44 mg THC.
Scale the flower amount or the mold count to change the dose. Label each bomb with the number and the date.
What to Expect
THC has a molecular weight of 314 g/mol and high fat solubility. Human skin is a water-based barrier, so THC crosses it in small amounts without a penetration enhancer. A bath adds more limits: the oil floats, the water dilutes it, and contact time is short. Most users report scent, warm water, and softer skin. Claims of a full body high from a bath bomb come from marketing, not from measured blood levels.
Safety and Law
- Cannabis oil makes the tub slick. Rinse the tub after use.
- Patch test on your inner arm 24 hours before a full soak.
- Keep bombs away from children and pets.
- Skip open cuts and broken skin.
- Cannabis is Schedule I under federal US law. Bath products with THC are legal in states with adult-use or medical programs. Do not carry them across state lines.