It could be a combination of things. First it can take months for your body to cleanse itself from animal foods. Ask yourself what are you eating right now? If you live off mostly processed vegetarian junk then you will be drained all the time because you are lacking proper nutrition. Also if you are still consuming dairy and eggs (you said vegetarian not vegan), then that is keeping you in that drained state as there is nothing worse than consuming dairy! So take a good look at your diet. All you really need to take is B-12 if you are vegan, as long as you are eating real healthy plant food. Just saying you are vegetarian or vegan doesn't equal healthy if you consume far too much junk food. Too much salt, sugar and fat in your diet will also drain the life out of you and everything processed has all or one of those in it. Salt, sugar and fat are highly addictive and very bad to eat, so try and remove all or most of those from your diet and you will feel better. It takes time to detox you body of the bad stuff, but eventually you will feel great and alive and never drained as long as you eat proper plant foods. Vitamin supplements are not the answer. Eating properly is. Plus every body is different and no one can really tell your to take this vitamin or this supplement because no one really knows what you need or how much you need. Even nutritionists can only guess. You can get tested to see if your body is lacking something, but as long as you eat a variety of plants you should be fine, unless there is some condition you have. Believe me there is no magic pill, you must eat properly. Vitamins are way too concentrated so the stuff that stores in your body is too much and the stuff like Vitamin C that washes out of your body daily, so that you are putting in way too much in a pill form. In essence you are literally pissing away most of your money! Far cheaper to eat healthy in the first place than buy pills.