How are injections given without injuring actors?

I remember talking at some stage to a makeup artist from a film set. They had spring-loaded syringes where the actual needle would retract into the body of the syringe. This way they get a realistic pucker effect where the needle presses against the skin.

I am late to this discussion, but the Weapons Specialist Ltd company makes retractable syringes and all sorts of other cool props. The website includes a video of the syringe in action.

While I do not have any official sources, I do not see them getting any actual syringes for a movie. It is fake as with most whether they do it with CGI (which seems a bit over the top when you have) trick syringes, or I've seen before where they just imply the shot with a cut-away.

All three types of techniques are used.

1. Fake appendages. You can use a real needle in these. Common when the appendage in question will be changed or explode or anything. All practical effects.

2. CGI. In bigger productions, this can be a viable alternative to a prop. Most often though, it will be a combination of a prop and CGI.

3. But the most common is special effects props. Nothing beats a solid prop in your hand.

You can see the needle retracted into the syringe here:

A DIY one:

I own In The Shadows props www.intheshadows.ca. In all unionized productions, an actor will never be punctured with a syringe. Movie prop syringes range from $80-$100 for low end products where the needle will retract, to $400 - $800 where the needle will retract, is spring loaded, and will come back out as the needle is pulled from the arm. Also, the High end have a second system, where liquid can be filled into the needle (blood drawn, or what ever color liquid is coming out of your alien), or liquid injected (clear, Heroin, floating particles, etc). This is done via a 4 foot hose connected to the side of the syringe. At the other end is a vile with a bladder. That is where fluid goes to when injected, or fluid comes from when liquid is drawn from the needle. We make custom props. However, the high end syringes take very specialized materials and craftsmanship to make. So we purchase from trusted suppliers. One of the best effects is having a clear liquid (i.e. heroin) in the syringe. The bladder then has red liquid (blood), and the tube is also full of blood. The syringe is injected (pushed against skin, and spring loaded needle goes into shaft), and a little blood is drawn into the syringe to confirm you hit a vein. This close up is a deal seller on film. Then the syringe is depressed shooting the heroin (into the bladder at the end of the hose). The shot usually changes here, as the specialty syringe is replaced with a real (dulled) syringe (another prop too long to talk about). And with a little movie adhesive, left in the arm/ leg / wherever, as the actor removes the rubber band to get stoned.

Hope this helps. P.S. as a pro in the industry, I would never recommend trying to make your own spring loaded needle. You never want to put an actor at risk.

Blunt ends are readily available for syringes. A normal syringe has a diagonal cut on the hollow needle, milled to be very sharp. A blunt is square cut and milled to round out sharp edges. It will not penetrate skin unless you use such extreme force as to probably bend the needle. You can then fill the interior of the needle with epoxy.

That syringe can be easily modified by turning down the plunger to fit a white sleeve, sealing that at the bottom with epoxy, and then drilling a hole through the plunger gasket so the liquid goes up into the white sleeve (or vice versa). If you did it simply, giving the white sleeve an open top, it would be easy to fill/drain, but an actor would have to be careful to hold the syringe not too horizontally.