If you think there was an overdose, call your local poison control center or ER right away. Signs of a very bad reaction to the drug. These include wheezing; chest tightness; fever; itching; bad cough; blue or gray skin color; seizures; or swelling of face, lips, tongue, or throat. Blood in the urine. Not able to pass urine. Any bruising or bleeding. Very bad dizziness or passing out. Very loose stools (diarrhea). Very upset stomach or throwing up. Any rash. Side effect or health problem is not better or you are feeling worse.
The common side effects of oxymetholone include depression , lethargy , headache , swelling , rapid weight gain , priapism , changes in skin color, urination problems, nausea , vomiting , stomach pain (if taken on an empty stomach), loss of appetite , jaundice , breast swelling in men, feeling restless or excited, insomnia , and diarrhea .  In women, side effects also include acne , changes in menstrual periods , voice deepening , hair growth on the chin or chest , pattern hair loss , enlarged clitoris , and changes in sex drive .   Because of its 17α-alkylated structure, oxymetholone is hepatotoxic .  Long term use of the drug can cause a variety of serious ailments, including hepatitis , liver cancer , and cirrhosis ; therefore periodic liver function tests are recommended for those taking oxymetholone. 
Proviron is very effective compound, daily dosage of 50 mg is sufficient although some men do 100 and even 250 mg/day. Athlete normally takes one 25 mg tablet in the morning- and the other one at the evening. In some cases, even one 25mg tablet is enough. Combo of 50 mg Proviron per day and 20 mg of Nolvadex per day results in almost complete suppression of estrogen. However, keep in mind that estrogen is not absolute Evil, it also plays important role in muscle building. Complete suppression of estrogen means lower gains, so one should keep a balance and decrease estrogen level only to the point when it makes no side effects but still produces positive ones.