Is there anything wrong with not having a menstrual period if I never want to have children?

I'm 21 years old, and I haven't had a menstrual period for two years now. I am in excellent physical shape--I exercise everyday, eat a balanced diet, and don't drink, smoke, or do drugs. I do take a half dose of Lexapro (5 mg). Yes, I realize that the amenorrhea is likely caused by my low body fat, and that it could permanently damage my reproductive system. However, I have never wanted, currently do not want, and am 100% sure that I will never in the future want to have children. I am also not interested in ever having a sexual relationship with anyone, so I'm not seeing this amenorrhea as a possible form of "birth control." I just don't mind not having a period--in fact, it's nice to not have to worry about the hassle that comes with a period.

So, here's the question: given my lack of desire to have children, is there any reason for me to take measures to restart my period?

It's not the lack of period that's bad, it's the other conditions that accompany it and that you can't notice.
Exercise amenorrhea is often accompanied with bone density loss, and osteoporosis in the future, hair loss, unwanted hair on the face, your chest, and arms, and heart problems.
Plus, you can't be 100% if your missed periods are due to low body fat % or to hormonal problems. See a doctor to be on the safe side.

That's a question for your doctor. IDK.

At your age, I never wanted children. Still at 28 I didn't want children. Then it hit me one day and I've never wanted children more in my life! You need to discuss it with your doctor about any other health concerns you could be facing.

That is completely personal for you, but is something that you should talk to your doctor about. Definitely see a doctor. It could be something more serious.

It's not my place to say, but just because you don't want to have children and don't think you ever will, I can tell you from personal experience that if you ruin all chances of that now, and then change your mind in the future, you will have to live with horrible pain and disappointment. You are still so young. Don't completely count it out. Some amazing guy could come along and change your mind. That's what happened to me.

Again, none of my business, but you put it out there. Generally, (not always, but generally), people who have no interest in a sexual relationship of any kind have something deeper that they need to deal with, such as abuse in their past (sorry, but it's true. Also from experience). If this is the case, you really should seek help. It could change your life.

But, I don't know you or your personal reasons, so I will go back to my original statement: See your doctor to make sure that it isn't something more serious. Good luck, whatever you decide to do! Be healthy!

I think you are risking a lot. Just because you don't want to have kids, you should not still take a risk at damaging your reproductive system. Those organs are not only for child birth but also female hormones. I think that's on hell of a risk you are taking. there are safer ways to go about not having a frequent period. You need to talk to your doctor. And yes you may be 100% positive that you don't want kids, but life changes and I was once 100% sure I never wanted kids. Yrs. later, I have 2 and never thought I would want kids. I'm not saying you will, but don't ever presume that you will know what you will want out of life in 10 yrs. from now. I think you could damage more then oyu realise and this damage could affect way more then just bering children. Also, not having a period, can be a sign of other serious health issues.

One in five women, in the USA don't want children. Don't think anything of it.

I can't help with the period.

I think when you are positive you don't want children, there's no need to swallow hormones, just to have your period again. I have a very irregular cycle, I usually only get my period every two or three months, one time I didn't have a period for six months. I'm not taking anything either, because I neither want to get pregnant, not do I take oral contraceptives. There's no need for me to have a regular cycle.
However, I think you should have a full check up in order to find out if you are really healthy. Menorahs can have many causes (one of them being your low body fat), including cancer.