This is probably a placebo effect. A lot of what you are reading on the internet about semen intake improving a person's vitality is a sexual fantasy.
There are claims (from people with little to no medical knowledge or understanding of anatomy and body chemistry) that the small amount of testosterone contained in male ejaculate can affect a woman when it gets into her body. Supposedly the raised testosterone level can be good for her mood and her sex drive. But this is not like when a middle aged man is suffering from low testosterone and takes a prescription dose of it.
As for the testosterone making a woman's skin glow, if anything female hormones are responsible for that. That is why when a woman is pregnant and her female hormone levels are through the roof, people will say oh she is glowing. On the other hand, in cases of women with higher testosterone levels than women normally have, their skin suffers from symptoms such as acne. Some women even take anti-androgen medication to lower their testosterone levels to get their skin's sebum production back under control.
Finally, the oral intake of semen cannot significantly raise testosterone levels because the stomach metabolizes it before it can get into the bloodstream and have any substantial effect on the body. As for vaginal intake of semen, only a negligible amount of testosterone will be absorbed from that area, if any. This leaves something you neglected to mention, the anal intake of semen. Look at it this way, some people take alcohol enemas and get far drunker than oral drinking and run a far greater risk of dying from alcohol poisoning this way. So if the small amount of testosterone in semen could have an effect on a woman at all, it would have to be administered anally. However, testosterone is taken in much higher doses than what semen contains, and in the form of intramuscular or subcutaneous injections, if it is going to be any kind of effective treatment. For example, a middle-aged man suffering from diminished testosterone cannot simply have someone with high testosterone ejaculate into his rear and get his testosterone levels back up. He would require a prescription for testosterone injections if he wanted/needed to get back to normal testosterone levels.