AROMASIN-25 is an post cycle steroid, or like aromatase inhibitor it is also known as Aromasin and is made by Global Anabolic.
AROMASIN-25 is a steroidal suicide aromatase inhibitor, which means that it lowers estrogen production in the body by blocking the aromatase enzyme, the enzyme responsible for estrogen synthesization.
Exemestane was developed to fight breast cancer in post-menopausal women, who need a particularly aggressive therapy, and for whom first line defenses such as SERMS (Tamoxifen) have not worked. This should be our first clue in inferring that this stuff is pretty strong, or at least stronger than some of the other compounds which are used to fight breast cancer.

AROMASIN-25 averages an 85% rate of estrogen suppression, so it´s clearly a very effective agent for bodybuilders and other athletes wanting to avoid estrogen related side effects such as gyno, acne, or water-retention brought on by aromatizing steroids. Specifically, AROMASIN-25 dose this by selectively inhibiting aromatase activity in a time-dependent and irreversible manner.
As with most of the compounds in this class, it also causes a reasonable rise in testosterone levels, and as you may have guessed, this rise in testosterone means that AROMASIN-25 can also cause androgenic sides. As you can see from the chart below, exemestane is very effective at both lowering estrogen (estradiol) and raising testosterone: Estrogen and androgen plasma levels after 10 d of daily exemestane (25 or 50 mg) in healthy young males. To convert to Systeme International units: estradiol, picomoles per liter; estrone, picomoles per liter; androstenedione, nanomoles per liter; and testosterone, nanomoles per liter.
So we can see that 25 mgs is a very effective dose from that chart, right? As an added benefit, exemestane not only increases testosterone and lowers estrogen, but it also increases IGF levels. Additionally Worth noting is that AROMASIN-25 may possibly be less harsh on blood lipids than some of the other (similar) compounds we use in the world of bodybuilding or athletics. It also has, at best no effect on IGF, and at worst could lower it. AI´s are very tricky with regards to inconsistencies in IGF levels.
Unfortunately, you need to take Exemestane for a week to reach steady blood plasma levels of it, and exemestane has a half life of 27 hours.
The ability of exemestane to lower estrogen levels by the aforementioned 85% makes it a very nice choice for use in any cycle where aromatizing steroids are used. In addition, since it´s not too harsh at all on blood lipid profiles, it´s a very good choice for longer cycles. It´s ability to raise both testosterone levels also seem to suggest that it would be a very nice addition to a Post-Cycle-Therapy (PCT).

SIDE EFFECTS:
All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Exemestane: anxiety; back, joint, muscle, or limb pain; constipation; coughing; diarrhea; dizziness; fatigue; flu-like symptoms; hair loss; headache; hot flashes; increased or decreased appetite; increased sweating; joint pain; nausea; stomach pain or upset; tiredness; trouble sleeping; weight gain; vomiting.