A few of the interventions showed limited evidence of effectiveness, including the following:

Rosemary oil: A trial in 100 men found that hair regrowth with topical rosemary oil was similar to that from treatment with 2% minoxidil (an effective hair loss medication). Another trial found that a topical solution containing rosemary oil, olive oil, and saw palmetto in addition to minoxidil increased hair thickness more than minoxidil alone.
Teak leaf: A trial in men only found that topical teak leaf extract increased hair counts more than a placebo but was less effective than 5% minoxidil.
Edelweiss: A trial predominantly consisting of women found that topical edelweiss extract increased hair density more than a placebo.

Other interventions included oral amla, oral ginger, and topical squill bulb extract.

Plant-based botanicals for hair loss Original paper