Norplant 
noun [mass noun] trademark
A contraceptive for women consisting of small rods implanted under the skin which gradually release the hormone levonorgestrel over a number of years.The five-year contraceptive implant Norplant also can affect mood, although hormone levels tend to return to normal soon after the rods are surgically removed....
- At present there are only two types of contraceptive implant used in the UK, Norplant and Implanon.
- Conversely, the progestin-only ring acts similar to Norplant, but may only last for 1 or 2 years.
Origin
1980s: from (levo)nor(gestrel) (im)plant.
- on the prod
- on the prowl
- on the quiet
- on the rack
- on the rails
- on the rebound
- on the right (or wrong) track
- on the right side of
- on the rise
- on the road
- on the rocks
- on the rope
- on the ropes
- on the run
- on the same page
- on the scent
- on the score of
- on the scrounge
- on the sea
- on the shelf
- on the sick
- on the side
- on the side of the angels
- on the skew
- on the skids