Historically low gilt yields have driven down the incomes available via annuities or drawdown by almost a quarter, Skandia said.
Skandia said the latest round of quantitative easing has put pressure on gilt yields, which has driven down the Government Actuary Department (GAD) rate used to calulate pension payments.
GAD is the rate pension providers use to calculate annuity rates, and the rate at which investors can withdraw pension funds via capped drawdown.
Combined with stock market losses over the summer, retirement incomes are down by almost a quarter since April, Skandia said.
According to the life company's research, if an individual's pension fund mirrored the behaviour of the FTSE 100 - which fell from 6041.13 points to 5291.26 between April and October - a £100,000 pot would now be worth just £87,600.
With yields on 15 year gilts falling from 4% to 3% over the same period a 60-year-old woman taking an income now, either through capped drawdown or an annuity would receive just £4,380, compared to £5,500 in April, Skandia said.
Adrian Walker, head of retirement planning at Skandia said there are some methods of cushioning the blow for investors retiring in November.
"Phasing money into income withdrawal and choosing arrangements with flexible review options will help meet short term income needs and will help provide opportunities to benefit from any future market upturn," said Walker.
"This could be combined with the need to use other savings to top up any temporary shortfall in income payments."
£92bn transferred since 2015
Achievements, charity work and other happy snippets
Since first announcement