Last updated: October 2026
To make CBD bath bombs, mix bicarbonate of soda, citric acid, cornflour and Epsom salts, then slowly add melted shea butter or coconut oil blended with your CBD oil, spritzing with a little water until it holds like damp sand. Press into moulds and dry overnight. This recipe makes two large bath bombs with about 100mg of CBD each.
Below: ingredients, step-by-step method, tips to stop them crumbling, what CBD in the bath can and can’t do, and safety.
Ingredients
| Ingredient | Amount | Job |
|---|---|---|
| Bicarbonate of soda | 120g | Fizz (with citric acid) |
| Citric acid | 60g | Fizz |
| Cornflour | 60g | Slows the fizz; silky water |
| Epsom salts | 60g | Texture |
| Shea butter or coconut oil, melted | 1 tbsp | Carries the CBD; softens skin |
| CBD oil | 200mg in total (for example 2ml of a 1000mg 10ml oil) | The CBD |
| Essential oil (optional) | 5 to 10 drops | Scent |
| Water or witch hazel in a spray bottle | A few spritzes | Binds the mixture |
You’ll also need two bowls, a whisk and a bath bomb mould. An unflavoured oil works best, such as our Broad Spectrum CBD Oil. See CBD oil strengths explained.
Method
- Mix the dry ingredients in a large bowl, breaking up any lumps.
- Mix the wet ingredients: stir the CBD oil and essential oil into the melted shea butter or coconut oil.
- Combine slowly: drizzle the oil mixture into the dry ingredients, whisking all the time.
- Spritz lightly with water or witch hazel, mixing between sprays, until it holds together when squeezed, like damp sand. Too much water and it will start to fizz.
- Pack each half of the mould firmly, slightly overfilled, then press the halves together.
- Leave in the mould for a few minutes, unmould gently, and dry overnight somewhere dry.
- Store in an airtight container and use within a few weeks.
Tips for perfect bath bombs
| Problem | Fix |
|---|---|
| Crumbles when unmoulded | Too dry: add another spritz and pack more firmly |
| Fizzing while you mix | Too wet or humid: spray less, mix faster, work in a dry room |
| Cracks as it dries | Too much liquid or packed unevenly |
| Oily ring in the bath | Use less butter, or add a little polysorbate if you make them often |
Does CBD in the bath do anything?
Probably not much on its own. CBD is spread through a whole bath of water, and there’s no evidence that meaningful amounts pass through the skin from bath water. Epsom salts are similar: there’s little evidence magnesium is absorbed through the skin. The real benefit is the ritual: a warm bath before bed can help you wind down. For CBD you can measure, take it by mouth or use a balm on a specific area. See how to take CBD oil and CBD balm.
Safety
- Patch test new essential oils first; they’re a common cause of skin irritation.
- Avoid if you have broken skin or eczema flaring, and keep bath bombs away from children and pets.
- Take care getting out: oils make the bath slippery.
- Citric acid can sting eyes; wear gloves if your skin is sensitive.
- Selling them: cosmetics sold in the UK need a safety assessment and must meet cosmetics rules, so these are for home use.
- Pregnancy: check essential oils with your midwife; we don’t recommend our products during pregnancy or breastfeeding.
FAQs
How much CBD should I put in a bath bomb?
This recipe uses 200mg for two large bath bombs, about 100mg each. More won’t make a measurable difference in a full bath.
Do CBD bath bombs work?
There’s no evidence much CBD is absorbed from bath water. Enjoy them as a relaxing ritual rather than a way to take CBD.
Can I use CBD balm instead of oil in a bath bomb?
You can melt a little in with the shea butter, but oil mixes more evenly.
Why are my bath bombs crumbling?
The mixture is too dry or not packed firmly. Add a spritz of water or witch hazel and press harder into the mould.
How long do homemade bath bombs last?
Use them within a few weeks, stored airtight and dry, before they lose their fizz.
Sources
- Gröber U et al. Myth or reality: transdermal magnesium? Nutrients, 2017.
- GOV.UK. Making cosmetic products available to consumers in Great Britain.
