Sweet almond oil is a base or carrier oil
Bitter almond oil is an essential oil
Sweet almond oil comes from the sweet almond tree, prunus dulcis, var. amygdalus, this is the tree that produces the commercial variety of almonds that we eat. Its flowers are usually white.
Bitter almond comes from the almond tree, prunus dulcis, var. amara. Its flowers are normally pink.
Bitter almonds are slightly broader and shorter than sweet almonds, and they contain only about 50% of the carrier/fixed oil that is found in sweet almonds.
Sweet almond oil is one of the top oils for hair (and skin); it is rich in protein, vitamins and mineral oils and therefore is considered nourishing and revitalising.
Unlike the essential oils lavender, rosemary, thyme and cedarwood which are known to stimulate hair growth and are all found in Neno Natural's Hair Growth Stimulator, bitter almond does not have any aromatherapy benefits at all. It simply exists as a fragrance essential oil.
If the bottle just says "Almond Oil" you can sometimes tell which of the two it is using the following indicators:
As an indication only, carrier oils are not potent and are used for a wide variety of functions so they normally come in plastic, larger bottles of 60 ml (2 0z ) at the very smallest.
Essential oils are highly potent so you only ever need a few drops at a time. They degrade and evaporate rapidly when exposed to light plus they eat into plastic so they're normally sold in 10 ml (0.35 oz) dark glass bottles.
With the above said, however, I would not buy a bottle that just says "Almond oil" because it may suggest a poor quality producer who doesn't even know the difference between the two.
For your hair you want "Sweet Almond Oil" so to avoid confusion don't bother buying a bottle that doesn't say "sweet" on it!
You might also like:
- Sweet and Bitter Almonds (Wikipedia)
- What is The Difference Between Sweet Almond & Bitter Almond (Susan Soaps)