Question about aging up

[Cersei]

So I started with one girl, I was still struggling with he career and barely made ends meet while she already had to mature into an adult. After that she met a Vampire and married him. I thought her life was flying by too fast and she would be old in no time before she got somewhere, plus I really love her and don't want her to get old and die. I decided since she converted to Vampirism and their kids are vampires too to adjust ageing process from options, I made it longest, telling myself that Vampires kinda live forever, but then no one else is ageing up around them too. Kids are teens and if I adjust to normal settings they will have to age up straight away, what will happen to their friends? and girlfriend/boyfriends? also They need to finish school and graduate right? how do I do that if they will age up fast after resetting from options. I figured that maybe I should use potions instead to delay their ageing, I know how to make young again, how long will it last for them to be young after drinking it? also what about Ambrosia? how often should it be taken in?
Anyone ever adjusted lifespan like me? I feel like I did a mistake, but then again they would all be old now.

[Pam]

Whether or not the teens would age up right away depends on how far their aging bar has progressed.  If it is all the way to the right, then yes, probably so.  But if there's still some space left, that same amount of space will still show after changing it back to normal aging.  For example, normal aging will say 2 days while long aging says 6 days, but the space on the bar will look the same.  The others around them should still be aging, but it takes a lot longer on the long setting.  Is that the reason you're thinking of going back to normal?

The Young Again potion takes the Sim back to the beginning of the Young Adult life phase.  From then, the Sim will live the regular amount of days unless the potion is taken again.  Ambrosia can be eaten to take the Sim back to the beginning of the current life phase.  As long as your Sim eats Ambrosia before aging up again, the Sim will stay in whatever life phase he was in at the time Ambrosia was eaten.

[Execution]

Kids are teens and if I adjust to normal settings they will have to age up straight away, what will happen to their friends? and girlfriend/boyfriends?

If their friends are close to aging up (in the last few days of Teenhood) on Long lifespan, they will probably age up later that same day on normal lifespan into Young Adults.

also They need to finish school and graduate right?

Technically, Teens don't even need to go to school, ever, but if you want to choose the trait when advancing into a Young Adult, you need to have at least an 'A'. If you already have this 'A', nothing will happen to you if they don't graduate.

I know how to make young again, how long will it last for them to be young after drinking it?

The teenagers cannot drink a Young Again potion. The Young Again potion only works for Young Adults, Adults, and Elders. However, Teens can make the potion. The Young Again potion will reset your Sim to the first day of Young Adulthood, which means that on Normal lifespan, they can go 42 Sim Days before becoming an Elder. Obviously, you get more benefit from the potion the later in life you drink it.

also what about Ambrosia? how often should it be taken in?

As Pam said, Ambrosia takes you to the first day of your current lifestage. This means that for maximum effectiveness, you should eat it right before your birthday.

[Pam]

The Young Again potion only works for Young Adults, Adults, and Elders. However, Teens can make the potion.

Can Young Again potion be made with the chemistry table?  I thought it was only available as a Lifetime Happiness Reward.

[folcon]

I think it can be gotten both ways Pam, though I would have to check.  Another way to keep them young is the Age Freeze Potion.  If I recall right, that will stop them aging all together, a potenal handy soultion in an Imortal dynasty after then have eaten their first ambrosia.

[Pam]

When in doubt, check Carl's Guide!  Yes, the Young Again potion can be made at the Chemistry Table.  I haven't played it much and stopped at the Imaginary Friend Metamorphium when I did.

[Cersei]

Can Young Again potion be made with the chemistry table?  I thought it was only available as a Lifetime Happiness Reward.

Yes one of my teens  discovered it while experimenting. It costs 5000 to make one, but obviously he got first one free,

[Joria]

I usually make all my Sims learn potion making just to get that first, free, Young Again potion!

[Cersei]

So when you drink young again it takes you back to young adult again right? and ageing starts again, Ambrosia just freezes ageing for a certain time? how long.

[Ricalynn]

Ambrosia doesn't freeze your age.  It takes you back to the beginning of your current lifestage.   So if you're an adult with 3 days til elder and you eat ambrosia.  Your life bar will now sit at 21 days til elder (on normal).


Also, folcon - The Age freeze potion is banned for the immortal dynasties. 

[Joria]

When playing for the HOF and following the rules to the letter, Age Freeze and Young Again potions are banned.  For my dynasty, which is not for the HOF, once my heir reaches elder and eats her first ambrosia, after that dish wears off she, or he, takes the Age Freeze because I got tired of having to remember to make new Ambrosia when the dish wears off.  It shows as being worn off when the lobster tail icon disappears.  At that point you have to eat more Ambrosia to not age any further.