Here is some facts on TSH, FSH, LH

I hope your studying for step 1 is going well.  Do study the First Aid.  The First Aid Q & A is an excellent source of questions to do while studying. 

First Aid for the USMLE Step 1 2011 (First Aid USMLE)

First Aid Q&A for the USMLE Step 1, Second Edition (First Aid USMLE)

I recommend making a realistic schedule and sticking to it.  You know yourself better so time yourself.  Have fun studying.  If you need a good Physiology book, I recommend:

Physiology: with STUDENT CONSULT Online Access (Costanzo Physiology).  Excellent book! 

Here is some facts on TSH, FSH, LH

• Glycoproteins ( with sugar moieties covalently linked to asparagines)
• Each is made up of an alpha and beta subunits (not covalently linked)
• Alpha subunits of TSH, FSH, LH are identical (synthesized from the same mRNA)
• Pairing of alpha and beta – in the ER and continues in the Golgi
• HCG – structurally similar to TSH, FSH and LH. 
• Glycoprotein with same alpha chain.