All effect animations on the player are lost when going through a portal:
a burning player still burns, but shows no flames
an invisible player seems to be visible again (but not for other players and mobs)
potion effect animations won't show up
When something is eaten, the effect animations will show again
Linked issues
is duplicated by
Comments
The potion effect still exists but your character is still visable. Once you eat/drink the invisablity comes back. Other potions are not affected.
Ok then it's different. In previous versions when going through portals would completely removed the effect
Also Confirmed.
EDIT- Animals/Mobs affected by this potion become visible when going through a portal.
Confirmed. As commented, the effect remains as mobs will ignore you, this is purely a rendering issue.
That bug affects to every single potion effect, I went with strength, resistance, fire resistance and water breathing, and they were gone.
Too bad the mod who did the title change, because the potion effect is lost, not the effect animation/only the effect animation.
Here are some screenshots that I think can proof the potion effects are lost when entering the portal from killing the ender dragon at the end.
When I went through the portal the Ender Dragon left on his death to return to the overworld, the potion effects I had were gone.
Steps to reproduce:
-Go to the end.
-Kill the dragon if it's not dead.
-Get potion effects, either by potions or by the /effect command.
-Check by the inventory key you still have them.
-Pass through the portal the ender dragon left on his death.
-Press the inventory key and you'll see you have no potion effects.
So title has to be changed back to "When going through portals with potion effects, they are lost.", or something similar.
Seriously, title should be changed to the one I mentioned before.
Any mod can change the title to the one I mentioned above, reading my how to reproduce guide? (Above too)

You're describing another issue.
This ticket is about losing the effect animations, not the effects itself.

MC-6431 reopened.
Still present in snapshot 13w42a.

Is this still a concern in the latest Minecraft version 14w04b? If so, please update the affected versions in order to best aid Mojang ensuring bugs are still valid in the latest releases/pre-releases.

The particles seem to appear in 14w21b,
probably already fixed 😉
Did you try this with other potions?
That was a known bug before.