Yes, age can be a factor.
After menopause this happened to me, resulting in sex becoming painful, to the point I couldn't have it. Over the counter lubricants did nothing really to help.
My doctor made several suggestions, including taking evening primrose oil. When she examined me at that time, she said I was really dry and red up there. Gross.
I decided to attack the problem at the source, and insert the evening primrose capsule into my vagina.
Note: I had to nip a hole in one end of the capsule, and squeeze a little of the oil out over the outer surface, because it hurt to insert the capsule dry. Make sure you push it up past your cervix. Wear a pad since a little oil will obviously come back out over time. Best time to do it is when you go to bed.
The first evening I did it, a few minutes after I started to burn. I thought "Oh great, don't tell me I'm allergic!" But the burning subsided after a few minutes.
The next evening, not as much burning, then none at all.
I realized it burned because the skin was SO dry, like if you put lotion on really chapped hands, and it burns.
Also, I've found it to be a much more satisfactory lubricant for sex. Expecially if you put a pill up there maybe an hour before, and then another right before, ahem, insertion. For the 2nd pill, insert in with a hole nipped off the end (I just bite it off) and squeeze the pill against the side of your vagina to get the oil out.
If anyone reading this thinks it's TMI, wait until you've been through menopause, or love someone who has.