Boldenone undecylenate , or boldenone undecenoate , sold under the brand names Boldane , Equipoise , Parenabol , and Vebonol among others, is a synthetic and injected anabolic–androgenic steroid (AAS) and androgen ester which is used in veterinary medicine , specifically in horses .      It is a long-acting ester prodrug of boldenone , which itself is a naturally occurring androgen (found in the scent gland of Ilybius fenestratus ) and dehydrogenated analogue of testosterone .   
EQ is created by chemically bonding the Boldenone hormone structure to a undecylenate ester, making the Boldenone into a raw material like syrup. The oily Boldenone Undecylenate can be mixed with sterile oil or a solvent like benzyl alcohol. This creates an oil based suspension that is then injectable directly into the muscle. EQ is versatile enough to be used for both bulking and cutting cycles. With cutting the EQ is stacked with Winstrol and Trenbolone and during bulking is stacked with testosterone and Dianabol (Enanthate or Cypionate). It is recommended that you use cycle aids during an EQ run, both N2Guard and Cardarine. Additionally, Arimidex or Aromasin, both Aromatase inhibitors, are necessary with Boldenone Undecylenate. Either, but not both Arimidex or Aromasin.
It should be noted that in theory if one was to consistently suppress your natural estrogen levels for a long period of time, this would negatively impact your health, including your cholesterol. Due to the ability of Letrozole- to inhibit estrogen so much, this should definitely be a concern to most users. However the research that has focused on the relationship between use of letrozole and cholesterol levels is rather inconsistent in it's findings. Many studies have concluded that the compound is detrimental to both a user's HDL and LDL cholesterol levels, while other research has found no link. Obviously individuals are best served to monitor their cholesterol while using any compound via blood tests however barring that, letrozole should simply not be run for extended periods of time if at all possible. Doing so could cause serious medical complications.
Along with the issues related to blood lipids is the fact that many users complain that their libido is dramatically reduced when using the compound. This is related to the fact that estrogen is partly responsible for the regulation of an individual's sex drive. Since Letrozole- is so potent it can often drive estrogen levels too low and this inhibits a user's libido. To avoid this users can lower dosages, but some anecdotally report that even extremely low doses of the drug can cause problems. If this is the case a less potent compound such as exemestane or anastrozole may be a more appropriate option.