http://www.tesnexus.com/downloads/file.php?id=27610
Requires SI + Cobl.
Version 8.
- This mod changes nearly all ingredient effects of nearly all the ingredients from Oblivion, Shivering Isles and Cobl.
The main purpose of this is to re-balance the effects compared to rarity and to bring back the feeling of
satisfaction of making a potion you actually need.
- Most Novice effects are now very weak (examples: Drain Magicka, Burden, Resist Poison). This is to prevent my self from always using Alchemy even when playing some barbarian character who would never pick flowers and fiddle with alchemy equipment.
- The Restore Attribute effects is now only found as 4th effect since I feel it needs nerfing.
- Restore Health and Damage Health is much less common now.
- There is now a great number of Fortify Skill effects in use.
- The Cure Disease effect is now rare.
- If for nothing else (if you like me love the Alchemy part of Oblivion) you can use this mod to try out a completely
different way of combining ingredients if you feel you know the vanilla effects by heart and want to see something new.
Installation:
Select which changes you wish by selecting the proper esp (choose only 1 esp):
MEIO.esp: Only the ingredient changes.
MIEO-ae.esp : Ingredient changes + re-balancing of the alchemy equipment (which makes your home brewed potion/poisons about 30 % weaker).
Take your pick and load it after your Cobl esp's.
Remember this mod requires you to have Shivering Isles and Cobl installed.
Reasons for this mod :
This mod began about 2? years ago after I had stumbled upon the mod Pestilent Afflictions, which makes diseases worse.
I quickly realized that the mod was practically irrelevant since all I had to do to avoid even the worst diseases was
to eat a mandrake root.
To fix this I removed the Cure Disease effect from mandrake root and from a few more ingredients. It did the trick and I was happy for a while getting riddled with diseases I could not simply cure in an instant.
After a while I returned to the CS to edit a few more things that I felt was an exploit or for another reason needed changing.
For instance, I always it was too easy to create poisons by using Sacred Lotus Seeds which is abundant several places. It was also too easy to create Restore Health potions since Fly Amanita Cap has this effect and the Imperial City is full of them.
Since it was so easy to create a lot of potions it began feeling like a chore to do it and I decided to change this
around so I would instead be happy or at least satisfied whenever I created a potion I really needed.
I began nerfing the effects that I felt was too abundant and also began testing effects that are normally only used in spells but not in ingredients. After much testing and many revisions (hence the "version 5" at the top of the page) where I've been scribbling down changes and had my table filled with papers to keep track of all the changes made (since the CS is not a good tool for this), I've now arrived at this mod. It is still undergoing development whenever I find something that is not right so don't be afraid to give feedback.
Lastly, this mod was made for me and my taste so it is probably not for anyone. After talking about this mod over at Delte's Immersion thread other peeps asked for me to release it and I so decided to do so.

Enjoy!
Documentation of occurrence of effects:
Drain Skill (Blade, Blunt, Marksman, Light Armor, Heavy Armor, Block)
Present from 2nd - 4th effect.
Number of each effect: 5 (meaning that for instance the 'Drain Blade' effect is present in 5 different ingredients.
Weakness to Fire, Frost, Shock, Magic, Poison & Normal Weapons.
Present from 2nd - 4th effect.
Number of each effect: 4
Fire Damage, Frost Damage & Shock Damage.
Present from 2nd - 4th effect.
Number of each effect: 6
Damage Health.
Present from 1st - 4th effect.
Number of this effect: 15
Restore Attributes.
Present only as the 4th effect.
Number of each effect: 4
Resist Frost, Resist Fire, Resist Shock.
Present from 1st - 4th effect.
Number of each effect: 9
Frost Shield, Fire Shield & Shock Shield.
Present from 1st - 4th effect.
Number of each effect: 8
Fortify Skill (All Skills, except Armorer & Alchemy since they have no effect).
Present from 2nd - 4th effect.
Number of each effect: 6
Compatibility:
Incompatible with mods that changes ingredients, but this can be sorted with load order.
MEIO-lvl.esp changes a few cobl leveled list that I know of no other mods that change.
MIEO-lvl-ae.esp also changes alchemy equipment but I know of only 1 mod which edits alchemy equipment (I got the idea from that mod. It's called Less Effective Alchemy Equipment.)
Version history:
Version 5 (earlier versions not released): Finally done enough to release it.
Version 6: Fixed two minor mistakes and made the effects overall a little more high-end (less nerfed).
Version 7: Fixed several minor inconsistencies and balance issues and posted documentation of my changes (to the OP).
Version 8: - Made sure all ingredients tagged as 'food' has fairly weak effects since those of us who uses realism mods, that require the PC to eat, won't waste good/strong ingredients on eating.
- More minor fixes.
- More Fortify Skill effects, less Resist Fire/Frost/Shock and less elemental Shield effects.
- Changed a few ingredients to reflect the next changes there will be made to COBL (as suggested by haama, migck, Vacuity and CorePC).
http://www.gamesas.com/bgsforums/index.php?s=&showtopic=1037455&view=findpost&p=15207205
I will continue to have my mod follow what team COBL decides about rarity of the ingredients so there's consistency. For that reason version 8 won't have have a version which changes COBL-leveled lists. I suggest to everyone to upgrade to the newest proposal/test version which I linked to above.