Generally both are mentioned "for women". They both have comparable half-lives & detection times - this means they both follow the same dosing schedule and clear the system on the same timeframe. The short half-life and detection times are preferred for women because you can stop and let the compound clear in a faster time than most other compounds if you don't like the sides and also the shorter duration in the system tends to keep more control of the sides if you do continue. Also both being oral (tho winstrol is also available as a water-based injectable, that you can also drink if you don't like needles), they are seen as "less hardcore" because there isn't all the stigma & drama associated w/ needles.
From a 'safety' standpoint, generally there is very little in the way of research related to any steroid & women, so we have to fall back on the studies that are available in other scenarios. Anavar is a pharma-grade compound that has been approved for, and widely used to treat wasting diseases. It is considered "safe". To this end it is the most 'predictable' and 'mild' in terms of sides, especially for women where even a tiny bump in testosterone levels can have dramatic impact on the female sytem because it immediately blows the natural proportion of test /estro /progest levels. You can't avoid the sides related to AAS use, but at least w/ anavar, it is fairly consistent, and mild relative to most others. On of the greatest advantages of any steroid is its 'recovery' aspect. You can train much more aggressively with the support of better recovery. Anavar will produce mild gains that are generally maintainable once you come off the cycle. The quality of those gains will depend on the quality of your diet & training. Leanness also comes w/ a cycle, but again, because the basic function of a steroid is to increase lean muscle mass, if you aren't already lean (e.g. 15% or smaller) the additional muscle mass can make you appear more "thick" than lean. Some women experience water retention on it as well. Typical sides are oily skin/hair/acne, water retention, interrupted period (expect this w/ anything that screws w/ your hormone profile), increased size / sensitivity of the clitoris. Occasionally some women experience headaches or nose bleeds from it. Nothing is guaranteed w/ any AAS, but var is the most reliable. (Assuming whatever you have is actually anavar and dosed correctly).
Winstrol is used pharmaceutically to treat hereditary angioedema, which causes episodes of swelling of the face, extremities, genitals, bowel wall, and throat. Stanozolol may decrease the frequency and severity of these attacks. It is much more anabolic than anavar and as such, the sides are less predictable and can be much more aggressive than noted in anavar. Included in the common sides are - oily skin/hair/acne, interrupted period, increased size/sensitivity of the clitoris, hairloss, voice change. Winstrol doesn't aromatize (convert to estrogen) so no water retention is expected. Further it has some anti-estrogenic aspects that can act to dry you out even more than otherwise. This is great for a cutting cycle, however in suppressing some estrogen, there is also the effect of dry joints which can be painful and promote joint / tendon injury. Effects are primarily good recovery and lean muscle gain, w/ the anti-estrogen effect, make a great cutter. In terms of predictabilty, it is often called the "snakebite drug" - it either likes you or it doesn't. Some people experience a low grade fever / feel sick within a week or two of running it.
what are the advantages and disadvantages of each of them? -- see above & pick out what you consider advantages & disadvantages for your particular goal.
is one better for strength?
- both - quality of strength will depend on the diet & training you support it with. Both produce generally maintainable results. Because winstrol acts as a bit of an estrogen suppressor, muscle hypertrophy will be limited (as muscles require water to grow). Usually for a cutter cycle, winstrol would be the more aggressive whereas anavar would be useful for both a cutting cycle or a bulker - w/ your diet & training driving your goals. And for women, anavar will always be the more predictable.
cutting?- either tho if you are ok w/ the potential for more sides, winstrol is the more aggressive for cutting. Anavar is more limited in that it has the potential to produce water retention (only way you'll know if you experience that is if you try it). In most cases, unless the water retention is really bad, the effect is minimal and for most women's competition categories doesn't matter that much (everyone is moving away from the ultra ripped look). At the worst, you would just drop the compound at 10-14 days out from your target show or event date to let your body naturally dump the water.
water retention?
- potentially w/ anavar
- winstrol doesn't aromatize.
duration of use?
- Women can run cycles at low doses for much longer than men can so for either a typical cycle could be 10 mg /day for 12 weeks. No need to increase. For anavar, the general max for dosing is at 20-25 mg /day (noting that just because I said this doesnt' mean you always need to use it - more is not better. The point is to find ehe amount that is sufficient for your goals as balanced w/ your tolerance for sides, and the balance of return on investment w/ it.) Cost-wise and sides-wise if you feel you need to go more than 20-25 mg /day, most people will switch to a more aggressive compound. Same w/ winstrol. Winstrol can also be dosed if you're doing the injectible, e.g. 50 mg E3D - if you work it out on a per day average, it still generally comes out to no more than 25 mg /day.
side effects?
- see above
dosage?
- see above
cost?
- anavar tends to be more expensive than winstrol. Historically winstrol has also been easier to get a hold of. (Usually more in liquid form.)
Really a big part of it becomes strict diet control, not unlike a man using an AAS compound that tends to create bloat.